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Quadratic form

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593: 2753: 1888: 325: 6373:
have completely characterized universal integral quadratic forms: if all coefficients are integers, then it represents all positive integers if and only if it represents all integers up through 290; if it has an integral matrix, it represents all positive integers if and only if it represents all
5981:
This debate was due to the confusion of quadratic forms (represented by polynomials) and symmetric bilinear forms (represented by matrices), and "twos out" is now the accepted convention; "twos in" is instead the theory of integral symmetric bilinear forms (integral symmetric matrices).
2400:(up to non-zero squares) can also be defined, and for a real quadratic form is a cruder invariant than signature, taking values of only "positive, zero, or negative". Zero corresponds to degenerate, while for a non-degenerate form it is the parity of the number of negative coefficients, 2614: 1359: 1714: 2210: 3314: 3870: 966: 1490: 588:{\displaystyle {\begin{aligned}q(x)&=ax^{2}&&{\textrm {(unary)}}\\q(x,y)&=ax^{2}+bxy+cy^{2}&&{\textrm {(binary)}}\\q(x,y,z)&=ax^{2}+bxy+cy^{2}+dyz+ez^{2}+fxz&&{\textrm {(ternary)}}\end{aligned}}} 281: 1192: 5832:. When the solution set is a paraboloid, whether it is elliptic or hyperbolic is determined by whether all other non-zero eigenvalues are of the same sign: if they are, then it is elliptic; otherwise, it is hyperbolic. 4227: 5644: 1663: 6149: 2081: 6050: 2304:, where these components count the number of 0s, number of 1s, and the number of −1s, respectively. Sylvester's law of inertia shows that this is a well-defined quantity attached to the quadratic form. 4897: 4488: 1994: 2748:{\displaystyle B={\begin{pmatrix}\lambda _{1}&0&\cdots &0\\0&\lambda _{2}&\cdots &0\\\vdots &\vdots &\ddots &0\\0&0&\cdots &\lambda _{n}\end{pmatrix}}} 5491: 3156: 330: 640:, and in the majority of applications of quadratic forms, the coefficients are real or complex numbers. In the algebraic theory of quadratic forms, the coefficients are elements of a certain 3960:
and these two processes are the inverses of each other. As a consequence, over a field of characteristic not equal to 2, the theories of symmetric bilinear forms and of quadratic forms in
2601: 1034:
The study of quadratic forms, in particular the question of whether a given integer can be the value of a quadratic form over the integers, dates back many centuries. One such case is
3719: 3437: 2505: 1883:{\displaystyle A={\begin{bmatrix}a&{\frac {b+d}{2}}&{\frac {c+g}{2}}\\{\frac {b+d}{2}}&e&{\frac {f+h}{2}}\\{\frac {c+g}{2}}&{\frac {f+h}{2}}&k\end{bmatrix}}.} 3577: 3702: 783: 1406: 117: 4349: 3958: 6836: 4072: 5527: 1497: 6082: 232: 1035: 1667:
So, two different matrices define the same quadratic form if and only if they have the same elements on the diagonal and the same values for the sums
1107: 6002: 5766:(we get the equation of an ellipsoid but with imaginary radii); if some eigenvalues are positive and some are negative, then it is a hyperboloid. 6620:
The bilinear form to which a quadratic form is associated is not restricted to being symmetric, which is of significance when 2 is not a unit in
4386: 1930: 6704: 6677: 6656: 6411: 6590:
The theory of quadratic forms over a field of characteristic 2 has important differences and many definitions and theorems must be modified.
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The theory of quadratic forms and methods used in their study depend in a large measure on the nature of the coefficients, which may be
1354:{\displaystyle q_{A}(x_{1},\ldots ,x_{n})=\sum _{i=1}^{n}\sum _{j=1}^{n}a_{ij}{x_{i}}{x_{j}}=\mathbf {x} ^{\mathsf {T}}A\mathbf {x} ,} 7005: 6920: 6882: 6848: 6802: 6764: 6737: 290:, which has only one variable and includes terms of degree two or less. A quadratic form is one case of the more general concept of 6204: 5826:
degenerates and does not come into play, and the geometric meaning will be determined by other eigenvalues and other components of
6696: 7000: 6900: 226: 1073: 6790: 5977:
a polynomial with integer coefficients (so the associated symmetric matrix may have half-integer coefficients off the diagonal)
2556: 3389: 2457: 202: 3532: 2205:{\displaystyle \lambda _{1}{\tilde {x}}_{1}^{2}+\lambda _{2}{\tilde {x}}_{2}^{2}+\cdots +\lambda _{n}{\tilde {x}}_{n}^{2},} 6974: 6956: 6794: 6521:), but at 2 they are different concepts; this distinction is particularly important for quadratic forms over the integers. 3663: 2268: 2043: 725: 2841:. Although their definition involved a choice of basis and consideration of the corresponding real symmetric matrix  6401: 64: 6969: 6951: 6058: 4294: 2946: 1127: 222: 31: 6530: 6912: 5762:. If all the eigenvalues are positive, then it is an ellipsoid; if all the eigenvalues are negative, then it is an 2067: 3910: 2071: 2027: 6168:
point of view, which was generally adopted by the experts in the arithmetic of quadratic forms during the 1950s;
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formulas show that the property of being a quadratic form does not depend on the choice of a specific basis in
2908: 2337: 2051: 2023: 163: 2340:(a mix of 1 and −1); equivalently, a nondegenerate quadratic form is one whose associated symmetric form is a 5670:. Classification of all quadratic forms up to equivalence can thus be reduced to the case of diagonal forms. 2275:
of the quadratic form, in the sense that any other diagonalization will contain the same number of each. The
6995: 6518: 6514: 5322: 3886: 3309:{\displaystyle q(x_{1},\ldots ,x_{n})=\sum _{i=1}^{n}\sum _{j=1}^{n}a_{ij}{x_{i}}{x_{j}},\quad a_{ij}\in K.} 2272: 2047: 707: 194: 159: 6964: 6541: 4768:. The notion of a quadratic space is a coordinate-free version of the notion of quadratic form. Sometimes, 6510: 4012: 3582: 3138: 2320: 1141: 291: 58: 50: 6599:
This alternating form associated with a quadratic form in characteristic 2 is of interest related to the
5679: 2057: 1133: 1115: 674: 314: 198: 186: 6866: 6640: 6560: 5948:
This is the current use of the term; in the past it was sometimes used differently, as detailed below.
6690: 5409: 5326:. This terminology also applies to vectors and subspaces of a quadratic space. If the restriction of 4956: 4264: 3516: 1122: 6946: 6383: 6370: 6176: 6161:
better understanding of the 2-adic theory of quadratic forms, the 'local' source of the difficulty;
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can be made to have only 0, 1, and −1 on the diagonal, and the number of the entries of each type (
2019: 741: 158:, and the quadratic form equals zero only when all variables are simultaneously zero, then it is a 130: 6449:
dictates the use of manifestly even coefficients for the products of distinct variables, that is,
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There are also forms whose image consists of all but one of the positive integers. For example,
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An integral quadratic form whose image consists of all the positive integers is sometimes called
4592: 3865:{\displaystyle b_{q}(x,y)={\tfrac {1}{2}}(q(x+y)-q(x)-q(y))=x^{\mathsf {T}}Ay=y^{\mathsf {T}}Ax.} 2341: 2063: 2031: 1061: 700: 686: 287: 54: 1092: 6916: 6878: 6844: 6798: 6760: 6733: 6700: 6673: 6652: 6426: 5518: 2945:. This stands in contrast with the case of isotropic forms, when the corresponding group, the 2533: 2253: 637: 190: 961:{\displaystyle q(x,y,z)=d((x,y,z),(0,0,0))^{2}=\left\|(x,y,z)\right\|^{2}=x^{2}+y^{2}+z^{2}.} 6926: 6888: 6854: 6816: 6770: 6743: 6721: 6686: 6552: 5708: 4940: 3604: 2994: 1997: 1709: 1485:{\displaystyle A={\begin{bmatrix}a&b&c\\d&e&f\\g&h&k\end{bmatrix}}.} 753: 737: 645: 182: 6812: 6930: 6892: 6874: 6858: 6840: 6820: 6808: 6774: 6747: 6648: 6187: 6165: 5849: 4232: 2213: 749: 682: 641: 625: 17: 2911:. The theorems of Jacobi and Sylvester show that any positive definite quadratic form in 6905: 6729: 4066: 2928: 2847:, Sylvester's law of inertia means that they are invariants of the quadratic form  1111: 757: 745: 655: 633: 621: 174: 141: 2318:
have the same sign is especially important: in this case the quadratic form is called
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squares by a suitable invertible linear transformation: geometrically, there is only
2075: 1145: 690: 678: 210: 170: 169:
Quadratic forms occupy a central place in various branches of mathematics, including
6416: 6396: 5712: 4595:, it is still possible to use a quadratic form to define a symmetric bilinear form 3987: 2386: 993: 276:{\displaystyle -\mathbf {x} ^{\mathsf {T}}{\boldsymbol {\Sigma }}^{-1}\mathbf {x} } 218: 178: 644:. In the arithmetic theory of quadratic forms, the coefficients belong to a fixed 5956:
Historically there was some confusion and controversy over whether the notion of
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is uniquely determined by the corresponding quadratic form. Under an equivalence
6828: 5759: 3465: 2812:. This is one of the formulations of Sylvester's law of inertia and the numbers 2423: 2246: 1068: 617: 137: 38: 2348:. A real vector space with an indefinite nondegenerate quadratic form of index 6759:. Cambridge Tracts in Mathematics. Vol. 106. Cambridge University Press. 6564: 6421: 6391: 5805: 5745: 5236: 4677:(and is thus alternating). Alternatively, there always exists a bilinear form 214: 46: 6513:, that is, if 2 is invertible in the ring, quadratic forms are equivalent to 5969:
the quadratic form associated to a symmetric matrix with integer coefficients
1106:, and found a method for its solution. In Europe this problem was studied by 6226: 6183: 5755: 4222:{\displaystyle q(v_{1},\ldots ,v_{n})=Q()\quad {\text{for}}\quad \in K^{n}.} 2998: 2379: 2056:
A fundamental problem is the classification of real quadratic forms under a
1077:, which includes, among many other things, a study of equations of the form 6672:, Carus Mathematical Monographs, The Mathematical Association of America, 5639:{\displaystyle q(x)=a_{1}x_{1}^{2}+a_{2}x_{2}^{2}+\cdots +a_{n}x_{n}^{2}.} 2256:
that is not necessarily orthogonal, one can suppose that all coefficients
1658:{\displaystyle q_{A}(x,y,z)=ax^{2}+ey^{2}+kz^{2}+(b+d)xy+(c+g)xz+(f+h)yz.} 6172: 5857: 1140:. Since then, the concept has been generalized, and the connections with 761: 308:
variables. In the cases of one, two, and three variables they are called
206: 3618:
with the same quadratic form, so it may be assumed from the outset that
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If a non-strict inequality (with ≥ or ≤) holds then the quadratic form
6406: 1137: 629: 2389:, concretely the class of the determinant of a representing matrix in 744:. In this way one may visualize 3-dimensional real quadratic forms as 6907:
Quadratic Forms with Applications to Algebraic Geometry and Topology
6873:. Die Grundlehren der mathematischen Wissenschaften. Vol. 117. 4250:
A finite-dimensional vector space with a quadratic form is called a
6144:{\displaystyle {\begin{pmatrix}a&b/2\\b/2&c\end{pmatrix}}.} 6911:. London Mathematical Society lecture note series. Vol. 217. 6446: 6053: 2242: 5265:
consists of the elements that are orthogonal to every element of
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of degree 2, which means that it has the property that, for all
1060:
are integers. This problem is related to the problem of finding
1038:, which determines when an integer may be expressed in the form 1026:
below for the definition of a quadratic form on a vector space.
2328:(all −1). If none of the terms are 0, then the form is called 1148:, and other areas of mathematics have been further elucidated. 6045:{\displaystyle {\begin{pmatrix}a&b\\b&c\end{pmatrix}}} 4028:
that has the following property: for some basis, the function
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positive definite real quadratic form of every dimension. Its
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An integral quadratic form has integer coefficients, such as
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as defined here is the associated symmetric bilinear form of
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a major portion of which was devoted to a complete theory of
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has been adopted as the standard convention. Those include:
6501:
in ternary forms. Both conventions occur in the literature.
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variables over a field of characteristic not equal to 2 is
2336:; this includes positive definite, negative definite, and 4483:{\displaystyle B(v,w)={\tfrac {1}{2}}(Q(v+w)-Q(v)-Q(w)).} 2517:
in the chosen basis. Under a change of basis, the column
2407:
These results are reformulated in a different way below.
1989:{\displaystyle B=\left({\frac {a_{ij}+a_{ji}}{2}}\right)} 302:
Quadratic forms are homogeneous quadratic polynomials in
6728:. London Mathematical Society Monographs. Vol. 13. 2066:
proved that, for every real quadratic form, there is an
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This generalizes to any number of variables as follows.
1385:
Consider the case of quadratic forms in three variables
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the actual needs for integral quadratic form theory in
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may be characterized in the following equivalent ways:
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are uniquely determined – this is Jacobi's theorem. If
2018:
So, over the real numbers (and, more generally, over a
970:
A closely related notion with geometric overtones is a
6561:§ 45 Reduction of a quadratic form to a sum of squares 6267:
that can each generate all positive integers, namely,
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In "twos out", binary quadratic forms are of the form
6011: 5808:(either elliptic or hyperbolic); if the corresponding 5357:
The orthogonal group of a non-singular quadratic form
4684:(not in general either unique or symmetric) such that 4412: 3752: 2629: 1729: 1421: 6085: 6005: 5985:
In "twos in", binary quadratic forms are of the form
5840:
Quadratic forms over the ring of integers are called
5530: 5486:{\displaystyle \forall x,y\in A\quad Q(xy)=Q(x)Q(y),} 5418: 4836: 4389: 4297: 4075: 3913: 3722: 3666: 3535: 3392: 3159: 2617: 2559: 2460: 2084: 1933: 1717: 1500: 1409: 1195: 786: 328: 235: 67: 4892:{\displaystyle Q(v)=Q'(Tv){\text{ for all }}v\in V.} 4811:
if there exists an invertible linear transformation
3510:
if there exists a nonsingular linear transformation
2547:
is transformed into another symmetric square matrix
6904: 6143: 6044: 5638: 5485: 4891: 4482: 4343: 4221: 3952: 3864: 3696: 3571: 3431: 3318:This formula may be rewritten using matrices: let 3308: 2960:, is non-compact. Further, the isometry groups of 2747: 2595: 2499: 2204: 2004:, and is the unique symmetric matrix that defines 1988: 1882: 1657: 1484: 1353: 960: 587: 275: 111: 5281:if the kernel of its associated bilinear form is 2271:states that the numbers of each 0, 1, and −1 are 144:numbers, and one speaks of a quadratic form over 6837:Ergebnisse der Mathematik und ihrer Grenzgebiete 5711:3-by-3 matrix. Then the geometric nature of the 4722:consisting of a finite-dimensional vector space 1064:, which appeared in the second millennium BCE. 748:. An example is given by the three-dimensional 5781:, then the shape depends on the corresponding 3976:Bilinear form § Associated quadratic form 286:Quadratic forms are not to be confused with a 5887:(over a field with characteristic 0, such as 2755:by a suitable choice of an orthogonal matrix 129:. The coefficients usually belong to a fixed 8: 5363:is the group of the linear automorphisms of 3591:be different from 2. The coefficient matrix 2773:is allowed to be any invertible matrix then 693:. The theory of integral quadratic forms in 6787:Introduction to Quadratic Forms over Fields 3624:is symmetric. Moreover, a symmetric matrix 2901:assumes both positive and negative values, 5754:are non-zero, then the solution set is an 3901:. Conversely, any symmetric bilinear form 2611:can be transformed into a diagonal matrix 2553:of the same size according to the formula 2252:If the change of variables is given by an 6117: 6102: 6086: 6084: 6006: 6004: 5735:depends on the eigenvalues of the matrix 5648:Such a diagonal form is often denoted by 5627: 5622: 5612: 5593: 5588: 5578: 5565: 5560: 5550: 5529: 5417: 4913:correspond to the equivalence classes of 4872: 4835: 4411: 4388: 4320: 4296: 4210: 4194: 4175: 4162: 4149: 4130: 4105: 4086: 4074: 3912: 3846: 3845: 3825: 3824: 3751: 3727: 3721: 3678: 3677: 3665: 3534: 3413: 3412: 3391: 3288: 3273: 3268: 3261: 3256: 3247: 3237: 3226: 3216: 3205: 3189: 3170: 3158: 2731: 2670: 2636: 2624: 2616: 2596:{\displaystyle A\to B=S^{\mathsf {T}}AS.} 2577: 2576: 2558: 2481: 2480: 2459: 2212:where the associated symmetric matrix is 2193: 2188: 2177: 2176: 2169: 2150: 2145: 2134: 2133: 2126: 2113: 2108: 2097: 2096: 2089: 2083: 1967: 1951: 1944: 1932: 1846: 1826: 1804: 1779: 1757: 1737: 1724: 1716: 1574: 1558: 1542: 1505: 1499: 1416: 1408: 1343: 1333: 1332: 1327: 1316: 1311: 1304: 1299: 1290: 1280: 1269: 1259: 1248: 1232: 1213: 1200: 1194: 949: 936: 923: 910: 869: 785: 575: 574: 553: 525: 497: 449: 448: 439: 411: 369: 368: 359: 329: 327: 268: 259: 254: 246: 245: 240: 234: 103: 75: 66: 6369:has 15 as the exception. Recently, the 5844:, whereas the corresponding modules are 699:variables has important applications to 6438: 5912:if and only if it is integer-valued on 5769:If there exist one or more eigenvalues 5375:: that is, the group of isometries of 4055:is a quadratic form. In particular, if 3432:{\displaystyle q(x)=x^{\mathsf {T}}Ax.} 2917:variables can be brought to the sum of 2511:is the column vector of coordinates of 2500:{\displaystyle q(v)=x^{\mathsf {T}}Ax,} 2378:particularly in the physical theory of 1036:Fermat's theorem on sums of two squares 27:Polynomial with all terms of degree two 6079:, represented by the symmetric matrix 5999:, represented by the symmetric matrix 3847: 3826: 3679: 3572:{\displaystyle \psi (x)=\varphi (Cx).} 3414: 3380:whose entries are the coefficients of 2578: 2482: 1334: 322:and have the following explicit form: 247: 4649:can no longer be recovered from this 2000:, defines the same quadratic form as 121:is a quadratic form in the variables 7: 4247:depends on the choice of the basis. 3966:variables are essentially the same. 3697:{\displaystyle B=C^{\mathsf {T}}AC.} 2432:be the matrix of the quadratic form 2279:of the quadratic form is the triple 1697:. In particular, the quadratic form 4907:-dimensional quadratic spaces over 2074:that puts the quadratic form in a " 1091:. He considered what is now called 225:(where the exponent of a zero-mean 6412:Ramanujan's ternary quadratic form 5852:). They play an important role in 5419: 2806:for −1) depends only on  2541:, and the symmetric square matrix 2438:in a given basis. This means that 2416:be a quadratic form defined on an 740:. This is a basic construction in 681:, in particular, in the theory of 25: 6153:Several points of view mean that 5145:is the associated quadratic form. 4774:is also called a quadratic form. 2873:(similarly, negative definite if 1067:In 628, the Indian mathematician 764:between a point with coordinates 677:have been extensively studied in 112:{\displaystyle 4x^{2}+2xy-3y^{2}} 30:For the usage in statistics, see 6397:Discriminant of a quadratic form 5877:; equivalently, given a lattice 4344:{\displaystyle Q(av)=a^{2}Q(v).} 2523:is multiplied on the left by an 2387:discriminant of a quadratic form 2026:different from two), there is a 1344: 1328: 1022: 269: 255: 241: 227:multivariate normal distribution 6871:Introduction to quadratic forms 6791:Graduate Studies in Mathematics 6645:Introduction to Quadratic Forms 5437: 4167: 4161: 3283: 3147:variables with coefficients in 710:, a non-zero quadratic form in 6668:; Fung, Francis Y. C. (1997), 6557:Introduction to Higher Algebra 6205:Lagrange's four-square theorem 5540: 5534: 5477: 5471: 5465: 5459: 5450: 5441: 4869: 4860: 4846: 4840: 4783:-dimensional quadratic spaces 4474: 4471: 4465: 4456: 4450: 4441: 4429: 4423: 4405: 4393: 4335: 4329: 4310: 4301: 4241:, although the quadratic form 4200: 4168: 4158: 4155: 4123: 4120: 4111: 4079: 3944: 3932: 3923: 3917: 3814: 3811: 3805: 3796: 3790: 3781: 3769: 3763: 3745: 3733: 3563: 3554: 3545: 3539: 3402: 3396: 3195: 3163: 2761:, and the diagonal entries of 2563: 2470: 2464: 2182: 2139: 2102: 2072:orthogonal change of variables 1643: 1631: 1619: 1607: 1595: 1583: 1529: 1511: 1238: 1206: 906: 902: 884: 880: 866: 862: 844: 838: 820: 817: 808: 790: 480: 462: 394: 382: 342: 336: 1: 6795:American Mathematical Society 6757:Arithmetic of quadratic forms 5804:, then the solution set is a 5285:. If there exists a non-zero 4034:that maps the coordinates of 2216:. Moreover, the coefficients 6670:The Sensual (Quadratic) Form 3953:{\displaystyle q(x)=b(x,x),} 2030:between quadratic forms and 1172:determines a quadratic form 6970:Encyclopedia of Mathematics 6952:Encyclopedia of Mathematics 6755:Kitaoka, Yoshiyuki (1993). 6692:Linear Algebra and Geometry 6607:Linear Algebra and Geometry 6059:Disquisitiones Arithmeticae 4585:When the characteristic of 4359:is not 2, the bilinear map 4353:When the characteristic of 2947:indefinite orthogonal group 2884:) for every nonzero vector 1152:Associated symmetric matrix 1128:Disquisitiones Arithmeticae 32:Quadratic form (statistics) 7022: 6913:Cambridge University Press 6555:(with E.P.R. DuVal)(1907) 6445:A tradition going back to 5344:is identically zero, then 5209: 4983:-bilinear form. A mapping 4919:-ary quadratic forms over 3973: 3033:from a finite-dimensional 2269:Sylvester's law of inertia 2068:orthogonal diagonalization 2058:linear change of variables 2044:Sylvester's law of inertia 2041: 648:, frequently the integers 29: 18:Isometry (quadratic forms) 6831:; Husemoller, D. (1973). 6689:; Remizov, A. O. (2012). 6605:Irving Kaplansky (1974), 6195:Universal quadratic forms 5682:in three dimensions, let 5016:associated quadratic form 4591:is 2, so that 2 is not a 3907:defines a quadratic form 3648:and the symmetric matrix 2372:−1s) is often denoted as 2028:one-to-one correspondence 7006:Squares in number theory 6833:Symmetric Bilinear Forms 6726:Rational Quadratic Forms 6515:symmetric bilinear forms 6374:integers up through 15. 5842:integral quadratic forms 5836:Integral quadratic forms 5212:Isotropic quadratic form 5189:, and the polar form of 4901:The isometry classes of 3708:associated bilinear form 3660:are related as follows: 2909:isotropic quadratic form 2862:is positive definite if 2338:isotropic quadratic form 2241:are determined uniquely 2052:Isotropic quadratic form 1911:, defined by the matrix 1494:The above formula gives 164:isotropic quadratic form 57:" is another name for a 7001:Real algebraic geometry 6965:"Binary quadratic form" 6581:is called semidefinite. 6519:polarization identities 6402:Hasse–Minkowski theorem 6247:and found 54 multisets 6052:This is the convention 5958:integral quadratic form 5792:. If the corresponding 4656:in the same way, since 4496:is symmetric. That is, 3887:symmetric bilinear form 3636:, the symmetric matrix 3603:may be replaced by the 2048:Definite quadratic form 1900:Given a quadratic form 1708:is defined by a unique 1142:quadratic number fields 708:homogeneous coordinates 292:homogeneous polynomials 229:has the quadratic form 195:second fundamental form 160:definite quadratic form 6963:A.V.Malyshev (2001) , 6945:A.V.Malyshev (2001) , 6145: 6046: 5640: 5487: 5402:has a product so that 4893: 4484: 4345: 4223: 3954: 3866: 3698: 3573: 3433: 3310: 3242: 3221: 3139:homogeneous polynomial 2749: 2597: 2501: 2206: 1990: 1884: 1659: 1486: 1355: 1285: 1264: 1134:binary quadratic forms 962: 675:Binary quadratic forms 589: 277: 113: 59:homogeneous polynomial 6542:Brahmagupta biography 6531:Babylonian Pythagoras 6146: 6047: 5820:, then the dimension 5680:Cartesian coordinates 5641: 5505:Every quadratic form 5488: 5390:If a quadratic space 5308:, the quadratic form 4894: 4485: 4346: 4224: 3955: 3867: 3699: 3574: 3488:-ary quadratic forms 3434: 3311: 3222: 3201: 2993:, but the associated 2750: 2605:Any symmetric matrix 2598: 2502: 2207: 2034:that determine them. 1991: 1885: 1660: 1487: 1356: 1265: 1244: 1074:Brāhmasphuṭasiddhānta 963: 716:variables defines an 590: 278: 199:differential topology 187:differential geometry 162:; otherwise it is an 114: 6647:, Berlin, New York: 6462:in binary forms and 6083: 6003: 5899:), a quadratic form 5528: 5501:Equivalence of forms 5416: 5410:algebra over a field 4834: 4734:and a quadratic map 4541:, and it determines 4387: 4295: 4265:homogeneous function 4073: 3911: 3720: 3710:of a quadratic form 3664: 3533: 3390: 3157: 3121:More concretely, an 2615: 2557: 2458: 2082: 2038:Real quadratic forms 1931: 1715: 1498: 1407: 1193: 1016:a quadratic form on 784: 326: 233: 65: 6666:Conway, John Horton 6371:15 and 290 theorems 6177:intersection theory 5848:(sometimes, simply 5764:imaginary ellipsoid 5632: 5598: 5570: 5495:composition algebra 5259:of a bilinear form 4874: for all  4490:This bilinear form 2856:The quadratic form 2198: 2155: 2118: 1062:Pythagorean triples 742:projective geometry 687:continued fractions 6687:Shafarevich, I. R. 6141: 6132: 6042: 6036: 5881:in a vector space 5846:quadratic lattices 5636: 5618: 5584: 5556: 5483: 5320:, otherwise it is 4889: 4480: 4421: 4341: 4219: 3950: 3862: 3761: 3694: 3569: 3429: 3306: 2839:indices of inertia 2745: 2739: 2593: 2497: 2426:vector space. Let 2307:The case when all 2202: 2175: 2132: 2095: 2032:symmetric matrices 1986: 1880: 1871: 1655: 1482: 1473: 1351: 1023:§ Definitions 974:, which is a pair 958: 701:algebraic topology 585: 583: 288:quadratic equation 273: 203:intersection forms 109: 49:with terms all of 6901:Pfister, Albrecht 6706:978-3-642-30993-9 6679:978-0-88385-030-5 6658:978-3-540-66564-9 6229:generalized this 5674:Geometric meaning 5092:A quadratic form 4875: 4420: 4165: 3760: 3087:and the function 3039:-vector space to 3001:) are different. 2995:Clifford algebras 2937:orthogonal group 2534:invertible matrix 2454:matrix such that 2326:negative definite 2321:positive definite 2267:are 0, 1, or −1. 2254:invertible matrix 2185: 2142: 2105: 1980: 1862: 1842: 1820: 1795: 1773: 1753: 638:analytic geometry 578: 452: 372: 191:Riemannian metric 183:orthogonal groups 61:). For example, 16:(Redirected from 7013: 6977: 6959: 6947:"Quadratic form" 6934: 6910: 6896: 6862: 6839:. Vol. 73. 6824: 6793:. Vol. 67. 6778: 6751: 6710: 6682: 6661: 6627: 6625: 6618: 6612: 6610: 6597: 6591: 6588: 6582: 6580: 6573: 6567: 6550: 6544: 6539: 6533: 6528: 6522: 6508: 6502: 6500: 6494: 6488: 6482: 6475: 6468: 6461: 6455: 6443: 6368: 6360: 6347: 6334: 6321: 6308: 6295: 6282: 6266: 6246: 6224: 6150: 6148: 6147: 6142: 6137: 6136: 6121: 6106: 6078: 6051: 6049: 6048: 6043: 6041: 6040: 5998: 5944: 5933: 5915: 5911: 5904: 5898: 5892: 5886: 5880: 5876: 5831: 5825: 5819: 5803: 5791: 5780: 5753: 5740: 5734: 5715:of the equation 5706: 5700: 5669: 5668: 5645: 5643: 5642: 5637: 5631: 5626: 5617: 5616: 5597: 5592: 5583: 5582: 5569: 5564: 5555: 5554: 5516: 5510: 5492: 5490: 5489: 5484: 5412:, and satisfies 5407: 5401: 5386: 5374: 5368: 5362: 5352:totally singular 5349: 5343: 5337: 5331: 5313: 5307: 5296: 5290: 5284: 5276: 5270: 5264: 5254: 5233: 5227: 5221: 5206:Related concepts 5200: 5194: 5188: 5178: 5168: 5144: 5133: 5115: 5110:There exists an 5105: 5088: 5078: 5023: 5013: 4982: 4976: 4954: 4948: 4941:commutative ring 4938: 4924: 4918: 4912: 4906: 4898: 4896: 4895: 4890: 4876: 4873: 4859: 4825: 4806: 4794: 4782: 4773: 4767: 4761: 4751: 4745: 4739: 4733: 4727: 4721: 4706: 4683: 4676: 4670: 4655: 4648: 4637: 4590: 4581: 4575: 4569: 4546: 4540: 4534: 4528: 4522: 4495: 4489: 4487: 4486: 4481: 4422: 4413: 4382: 4376: 4358: 4350: 4348: 4347: 4342: 4325: 4324: 4290: 4284: 4278: 4272: 4262: 4246: 4240: 4228: 4226: 4225: 4220: 4215: 4214: 4199: 4198: 4180: 4179: 4166: 4163: 4154: 4153: 4135: 4134: 4110: 4109: 4091: 4090: 4064: 4054: 4043: 4033: 4027: 4010: 4000: 3994: 3985: 3965: 3959: 3957: 3956: 3951: 3906: 3900: 3894: 3884: 3871: 3869: 3868: 3863: 3852: 3851: 3850: 3831: 3830: 3829: 3762: 3753: 3732: 3731: 3715: 3703: 3701: 3700: 3695: 3684: 3683: 3682: 3659: 3653: 3647: 3641: 3635: 3629: 3623: 3617: 3605:symmetric matrix 3602: 3596: 3590: 3578: 3576: 3575: 3570: 3528: 3505: 3499: 3493: 3487: 3478: 3463: 3438: 3436: 3435: 3430: 3419: 3418: 3417: 3385: 3379: 3373: 3363: 3347: 3336: 3328:with components 3323: 3315: 3313: 3312: 3307: 3296: 3295: 3279: 3278: 3277: 3267: 3266: 3265: 3255: 3254: 3241: 3236: 3220: 3215: 3194: 3193: 3175: 3174: 3152: 3146: 3136: 3126: 3117: 3086: 3076: 3066: 3044: 3038: 3032: 3018: 2992: 2972: 2965: 2959: 2944: 2922: 2916: 2906: 2900: 2889: 2883: 2872: 2861: 2852: 2846: 2829: 2820: 2811: 2805: 2796: 2787: 2778: 2772: 2766: 2760: 2754: 2752: 2751: 2746: 2744: 2743: 2736: 2735: 2675: 2674: 2641: 2640: 2610: 2602: 2600: 2599: 2594: 2583: 2582: 2581: 2552: 2546: 2540: 2532: 2522: 2516: 2506: 2504: 2503: 2498: 2487: 2486: 2485: 2453: 2443: 2437: 2431: 2421: 2415: 2403: 2399: 2377: 2371: 2365: 2359: 2334: 2333: 2317: 2303: 2266: 2240: 2211: 2209: 2208: 2203: 2197: 2192: 2187: 2186: 2178: 2174: 2173: 2154: 2149: 2144: 2143: 2135: 2131: 2130: 2117: 2112: 2107: 2106: 2098: 2094: 2093: 2014: 2003: 1995: 1993: 1992: 1987: 1985: 1981: 1976: 1975: 1974: 1959: 1958: 1945: 1926: 1910: 1889: 1887: 1886: 1881: 1876: 1875: 1863: 1858: 1847: 1843: 1838: 1827: 1821: 1816: 1805: 1796: 1791: 1780: 1774: 1769: 1758: 1754: 1749: 1738: 1710:symmetric matrix 1707: 1696: 1686: 1676: 1664: 1662: 1661: 1656: 1579: 1578: 1563: 1562: 1547: 1546: 1510: 1509: 1491: 1489: 1488: 1483: 1478: 1477: 1402: 1398: 1376: 1360: 1358: 1357: 1352: 1347: 1339: 1338: 1337: 1331: 1322: 1321: 1320: 1310: 1309: 1308: 1298: 1297: 1284: 1279: 1263: 1258: 1237: 1236: 1218: 1217: 1205: 1204: 1188: 1182: 1171: 1165: 1105: 1090: 1059: 1053: 1047: 1015: 1001: 991: 985: 967: 965: 964: 959: 954: 953: 941: 940: 928: 927: 915: 914: 909: 905: 874: 873: 780:and the origin: 779: 738:projective space 735: 723: 715: 698: 683:quadratic fields 672: 660: 653: 646:commutative ring 626:rational numbers 608: 602: 594: 592: 591: 586: 584: 580: 579: 576: 572: 558: 557: 530: 529: 502: 501: 454: 453: 450: 446: 444: 443: 416: 415: 374: 373: 370: 366: 364: 363: 307: 282: 280: 279: 274: 272: 267: 266: 258: 252: 251: 250: 244: 157: 147: 135: 128: 124: 118: 116: 115: 110: 108: 107: 80: 79: 21: 7021: 7020: 7016: 7015: 7014: 7012: 7011: 7010: 6991:Quadratic forms 6981: 6980: 6962: 6944: 6941: 6923: 6899: 6885: 6875:Springer-Verlag 6865: 6851: 6841:Springer-Verlag 6827: 6805: 6781: 6767: 6754: 6740: 6722:Cassels, J.W.S. 6720: 6717: 6715:Further reading 6707: 6685: 6680: 6664: 6659: 6649:Springer-Verlag 6639: 6636: 6631: 6630: 6621: 6619: 6615: 6604: 6598: 6594: 6589: 6585: 6576: 6574: 6570: 6551: 6547: 6540: 6536: 6529: 6525: 6509: 6505: 6496: 6490: 6484: 6477: 6470: 6463: 6457: 6450: 6444: 6440: 6435: 6387:-quadratic form 6380: 6366: 6363: 6350: 6337: 6324: 6311: 6298: 6285: 6272: 6248: 6230: 6208: 6197: 6188:algebraic group 6131: 6130: 6125: 6111: 6110: 6097: 6087: 6081: 6080: 6066: 6035: 6034: 6029: 6023: 6022: 6017: 6007: 6001: 6000: 5986: 5954: 5935: 5917: 5913: 5909: 5907:with respect to 5900: 5894: 5888: 5882: 5878: 5864: 5838: 5827: 5821: 5817: 5809: 5801: 5793: 5790: 5782: 5778: 5770: 5749: 5736: 5716: 5702: 5683: 5676: 5666: 5657: 5650: 5649: 5608: 5574: 5546: 5526: 5525: 5512: 5506: 5503: 5414: 5413: 5403: 5391: 5376: 5370: 5364: 5358: 5345: 5339: 5333: 5327: 5309: 5298: 5292: 5286: 5282: 5272: 5266: 5260: 5241: 5229: 5223: 5217: 5214: 5208: 5196: 5190: 5180: 5170: 5148: 5135: 5117: 5116:-bilinear form 5111: 5093: 5084: 5025: 5019: 4984: 4978: 4960: 4950: 4944: 4934: 4931: 4920: 4914: 4908: 4902: 4852: 4832: 4831: 4812: 4796: 4784: 4778: 4769: 4763: 4757: 4754:quadratic space 4747: 4741: 4735: 4729: 4723: 4711: 4685: 4678: 4672: 4657: 4650: 4639: 4596: 4586: 4577: 4571: 4548: 4542: 4536: 4530: 4524: 4497: 4491: 4385: 4384: 4378: 4360: 4354: 4316: 4293: 4292: 4286: 4280: 4274: 4268: 4258: 4252:quadratic space 4242: 4236: 4233:change of basis 4206: 4190: 4171: 4145: 4126: 4101: 4082: 4071: 4070: 4056: 4045: 4035: 4029: 4015: 4006: 3996: 3990: 3981: 3978: 3972: 3970:Quadratic space 3961: 3909: 3908: 3902: 3896: 3890: 3883: 3875: 3841: 3820: 3723: 3718: 3717: 3711: 3673: 3662: 3661: 3655: 3649: 3643: 3637: 3631: 3625: 3619: 3607: 3598: 3592: 3586: 3531: 3530: 3511: 3501: 3495: 3489: 3483: 3469: 3461: 3452: 3442: 3408: 3388: 3387: 3381: 3375: 3365: 3361: 3349: 3346: 3338: 3335: 3329: 3319: 3284: 3269: 3257: 3243: 3185: 3166: 3155: 3154: 3148: 3142: 3141:of degree 2 in 3132: 3122: 3088: 3078: 3068: 3046: 3040: 3034: 3020: 3014: 3007: 2974: 2967: 2961: 2949: 2938: 2918: 2912: 2902: 2891: 2885: 2874: 2863: 2857: 2848: 2842: 2830:are called the 2828: 2822: 2819: 2813: 2807: 2804: 2798: 2795: 2789: 2786: 2780: 2774: 2768: 2762: 2756: 2738: 2737: 2727: 2725: 2720: 2715: 2709: 2708: 2703: 2698: 2693: 2687: 2686: 2681: 2676: 2666: 2664: 2658: 2657: 2652: 2647: 2642: 2632: 2625: 2613: 2612: 2606: 2572: 2555: 2554: 2548: 2542: 2536: 2524: 2518: 2512: 2476: 2456: 2455: 2445: 2444:is a symmetric 2439: 2433: 2427: 2417: 2411: 2401: 2390: 2373: 2367: 2361: 2349: 2331: 2330: 2316: 2308: 2301: 2294: 2287: 2280: 2265: 2257: 2239: 2230: 2223: 2217: 2165: 2122: 2085: 2080: 2079: 2054: 2040: 2013: 2005: 2001: 1963: 1947: 1946: 1940: 1929: 1928: 1924: 1912: 1909: 1901: 1898: 1870: 1869: 1864: 1848: 1844: 1828: 1823: 1822: 1806: 1802: 1797: 1781: 1776: 1775: 1759: 1755: 1739: 1735: 1725: 1713: 1712: 1706: 1698: 1688: 1678: 1668: 1570: 1554: 1538: 1501: 1496: 1495: 1472: 1471: 1466: 1461: 1455: 1454: 1449: 1444: 1438: 1437: 1432: 1427: 1417: 1405: 1404: 1400: 1386: 1383: 1374: 1362: 1326: 1312: 1300: 1286: 1228: 1209: 1196: 1191: 1190: 1184: 1181: 1173: 1167: 1157: 1154: 1096: 1093:Pell's equation 1078: 1055: 1049: 1039: 1032: 1003: 997: 987: 975: 972:quadratic space 945: 932: 919: 883: 879: 878: 865: 782: 781: 765: 760:expressing the 750:Euclidean space 729: 717: 711: 694: 671: 663: 656: 649: 622:complex numbers 604: 598: 582: 581: 571: 549: 521: 493: 483: 456: 455: 445: 435: 407: 397: 376: 375: 365: 355: 345: 324: 323: 303: 300: 253: 239: 231: 230: 149: 145: 133: 126: 122: 99: 71: 63: 62: 35: 28: 23: 22: 15: 12: 11: 5: 7019: 7017: 7009: 7008: 7003: 6998: 6996:Linear algebra 6993: 6983: 6982: 6979: 6978: 6960: 6940: 6939:External links 6937: 6936: 6935: 6921: 6897: 6883: 6863: 6849: 6825: 6803: 6783:Lam, Tsit-Yuen 6779: 6765: 6752: 6738: 6730:Academic Press 6716: 6713: 6712: 6711: 6705: 6683: 6678: 6662: 6657: 6635: 6632: 6629: 6628: 6613: 6592: 6583: 6568: 6545: 6534: 6523: 6503: 6437: 6436: 6434: 6431: 6430: 6429: 6427:Witt's theorem 6424: 6419: 6414: 6409: 6404: 6399: 6394: 6389: 6379: 6376: 6362: 6361: 6348: 6335: 6322: 6309: 6296: 6283: 6269: 6225:is universal. 6196: 6193: 6192: 6191: 6180: 6169: 6162: 6140: 6135: 6129: 6126: 6124: 6120: 6116: 6113: 6112: 6109: 6105: 6101: 6098: 6096: 6093: 6092: 6090: 6039: 6033: 6030: 6028: 6025: 6024: 6021: 6018: 6016: 6013: 6012: 6010: 5979: 5978: 5975: 5970: 5967: 5953: 5952:Historical use 5950: 5837: 5834: 5813: 5797: 5786: 5774: 5675: 5672: 5662: 5655: 5635: 5630: 5625: 5621: 5615: 5611: 5607: 5604: 5601: 5596: 5591: 5587: 5581: 5577: 5573: 5568: 5563: 5559: 5553: 5549: 5545: 5542: 5539: 5536: 5533: 5502: 5499: 5482: 5479: 5476: 5473: 5470: 5467: 5464: 5461: 5458: 5455: 5452: 5449: 5446: 5443: 5440: 5436: 5433: 5430: 5427: 5424: 5421: 5369:that preserve 5332:to a subspace 5207: 5204: 5203: 5202: 5146: 4930: 4929:Generalization 4927: 4888: 4885: 4882: 4879: 4871: 4868: 4865: 4862: 4858: 4855: 4851: 4848: 4845: 4842: 4839: 4479: 4476: 4473: 4470: 4467: 4464: 4461: 4458: 4455: 4452: 4449: 4446: 4443: 4440: 4437: 4434: 4431: 4428: 4425: 4419: 4416: 4410: 4407: 4404: 4401: 4398: 4395: 4392: 4340: 4337: 4334: 4331: 4328: 4323: 4319: 4315: 4312: 4309: 4306: 4303: 4300: 4218: 4213: 4209: 4205: 4202: 4197: 4193: 4189: 4186: 4183: 4178: 4174: 4170: 4160: 4157: 4152: 4148: 4144: 4141: 4138: 4133: 4129: 4125: 4122: 4119: 4116: 4113: 4108: 4104: 4100: 4097: 4094: 4089: 4085: 4081: 4078: 4067:standard basis 4003:quadratic form 3971: 3968: 3949: 3946: 3943: 3940: 3937: 3934: 3931: 3928: 3925: 3922: 3919: 3916: 3879: 3861: 3858: 3855: 3849: 3844: 3840: 3837: 3834: 3828: 3823: 3819: 3816: 3813: 3810: 3807: 3804: 3801: 3798: 3795: 3792: 3789: 3786: 3783: 3780: 3777: 3774: 3771: 3768: 3765: 3759: 3756: 3750: 3747: 3744: 3741: 3738: 3735: 3730: 3726: 3716:is defined by 3693: 3690: 3687: 3681: 3676: 3672: 3669: 3583:characteristic 3568: 3565: 3562: 3559: 3556: 3553: 3550: 3547: 3544: 3541: 3538: 3457: 3450: 3428: 3425: 3422: 3416: 3411: 3407: 3404: 3401: 3398: 3395: 3357: 3342: 3333: 3305: 3302: 3299: 3294: 3291: 3287: 3282: 3276: 3272: 3264: 3260: 3253: 3250: 3246: 3240: 3235: 3232: 3229: 3225: 3219: 3214: 3211: 3208: 3204: 3200: 3197: 3192: 3188: 3184: 3181: 3178: 3173: 3169: 3165: 3162: 3129:quadratic form 3011:quadratic form 3006: 3003: 2973:are the same ( 2929:isometry group 2826: 2817: 2802: 2793: 2784: 2742: 2734: 2730: 2726: 2724: 2721: 2719: 2716: 2714: 2711: 2710: 2707: 2704: 2702: 2699: 2697: 2694: 2692: 2689: 2688: 2685: 2682: 2680: 2677: 2673: 2669: 2665: 2663: 2660: 2659: 2656: 2653: 2651: 2648: 2646: 2643: 2639: 2635: 2631: 2630: 2628: 2623: 2620: 2592: 2589: 2586: 2580: 2575: 2571: 2568: 2565: 2562: 2496: 2493: 2490: 2484: 2479: 2475: 2472: 2469: 2466: 2463: 2342:nondegenerate 2312: 2299: 2292: 2285: 2261: 2235: 2228: 2221: 2201: 2196: 2191: 2184: 2181: 2172: 2168: 2164: 2161: 2158: 2153: 2148: 2141: 2138: 2129: 2125: 2121: 2116: 2111: 2104: 2101: 2092: 2088: 2070:; that is, an 2039: 2036: 2024:characteristic 2009: 1984: 1979: 1973: 1970: 1966: 1962: 1957: 1954: 1950: 1943: 1939: 1936: 1920: 1905: 1897: 1894: 1879: 1874: 1868: 1865: 1861: 1857: 1854: 1851: 1845: 1841: 1837: 1834: 1831: 1825: 1824: 1819: 1815: 1812: 1809: 1803: 1801: 1798: 1794: 1790: 1787: 1784: 1778: 1777: 1772: 1768: 1765: 1762: 1756: 1752: 1748: 1745: 1742: 1736: 1734: 1731: 1730: 1728: 1723: 1720: 1702: 1654: 1651: 1648: 1645: 1642: 1639: 1636: 1633: 1630: 1627: 1624: 1621: 1618: 1615: 1612: 1609: 1606: 1603: 1600: 1597: 1594: 1591: 1588: 1585: 1582: 1577: 1573: 1569: 1566: 1561: 1557: 1553: 1550: 1545: 1541: 1537: 1534: 1531: 1528: 1525: 1522: 1519: 1516: 1513: 1508: 1504: 1481: 1476: 1470: 1467: 1465: 1462: 1460: 1457: 1456: 1453: 1450: 1448: 1445: 1443: 1440: 1439: 1436: 1433: 1431: 1428: 1426: 1423: 1422: 1420: 1415: 1412: 1382: 1379: 1370: 1350: 1346: 1342: 1336: 1330: 1325: 1319: 1315: 1307: 1303: 1296: 1293: 1289: 1283: 1278: 1275: 1272: 1268: 1262: 1257: 1254: 1251: 1247: 1243: 1240: 1235: 1231: 1227: 1224: 1221: 1216: 1212: 1208: 1203: 1199: 1177: 1153: 1150: 1031: 1028: 957: 952: 948: 944: 939: 935: 931: 926: 922: 918: 913: 908: 904: 901: 898: 895: 892: 889: 886: 882: 877: 872: 868: 864: 861: 858: 855: 852: 849: 846: 843: 840: 837: 834: 831: 828: 825: 822: 819: 816: 813: 810: 807: 804: 801: 798: 795: 792: 789: 758:Euclidean norm 746:conic sections 667: 661:-adic integers 634:linear algebra 573: 570: 567: 564: 561: 556: 552: 548: 545: 542: 539: 536: 533: 528: 524: 520: 517: 514: 511: 508: 505: 500: 496: 492: 489: 486: 484: 482: 479: 476: 473: 470: 467: 464: 461: 458: 457: 447: 442: 438: 434: 431: 428: 425: 422: 419: 414: 410: 406: 403: 400: 398: 396: 393: 390: 387: 384: 381: 378: 377: 367: 362: 358: 354: 351: 348: 346: 344: 341: 338: 335: 332: 331: 299: 296: 271: 265: 262: 257: 249: 243: 238: 211:four-manifolds 175:linear algebra 136:, such as the 106: 102: 98: 95: 92: 89: 86: 83: 78: 74: 70: 43:quadratic form 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 7018: 7007: 7004: 7002: 6999: 6997: 6994: 6992: 6989: 6988: 6986: 6976: 6972: 6971: 6966: 6961: 6958: 6954: 6953: 6948: 6943: 6942: 6938: 6932: 6928: 6924: 6922:0-521-46755-1 6918: 6914: 6909: 6908: 6902: 6898: 6894: 6890: 6886: 6884:3-540-66564-1 6880: 6876: 6872: 6868: 6867:O'Meara, O.T. 6864: 6860: 6856: 6852: 6850:3-540-06009-X 6846: 6842: 6838: 6834: 6830: 6826: 6822: 6818: 6814: 6810: 6806: 6804:0-8218-1095-2 6800: 6796: 6792: 6788: 6784: 6780: 6776: 6772: 6768: 6766:0-521-40475-4 6762: 6758: 6753: 6749: 6745: 6741: 6739:0-12-163260-1 6735: 6731: 6727: 6723: 6719: 6718: 6714: 6708: 6702: 6698: 6694: 6693: 6688: 6684: 6681: 6675: 6671: 6667: 6663: 6660: 6654: 6650: 6646: 6642: 6641:O'Meara, O.T. 6638: 6637: 6633: 6624: 6617: 6614: 6608: 6602: 6601:Arf invariant 6596: 6593: 6587: 6584: 6579: 6572: 6569: 6566: 6562: 6558: 6554: 6553:Maxime Bôcher 6549: 6546: 6543: 6538: 6535: 6532: 6527: 6524: 6520: 6516: 6512: 6507: 6504: 6499: 6493: 6487: 6481: 6474: 6467: 6460: 6454: 6448: 6442: 6439: 6432: 6428: 6425: 6423: 6420: 6418: 6415: 6413: 6410: 6408: 6405: 6403: 6400: 6398: 6395: 6393: 6390: 6388: 6386: 6382: 6381: 6377: 6375: 6372: 6358: 6354: 6349: 6345: 6341: 6336: 6332: 6328: 6323: 6319: 6315: 6310: 6306: 6302: 6297: 6293: 6289: 6284: 6280: 6276: 6271: 6270: 6268: 6264: 6260: 6256: 6252: 6245: 6241: 6237: 6233: 6228: 6223: 6219: 6215: 6211: 6206: 6202: 6194: 6189: 6185: 6181: 6178: 6174: 6170: 6167: 6163: 6160: 6159: 6158: 6156: 6151: 6138: 6133: 6127: 6122: 6118: 6114: 6107: 6103: 6099: 6094: 6088: 6077: 6073: 6069: 6063: 6061: 6060: 6055: 6037: 6031: 6026: 6019: 6014: 6008: 5997: 5993: 5989: 5983: 5976: 5974: 5971: 5968: 5966: 5963: 5962: 5961: 5960:should mean: 5959: 5951: 5949: 5946: 5942: 5938: 5932: 5928: 5924: 5920: 5908: 5903: 5897: 5891: 5885: 5875: 5871: 5867: 5861: 5859: 5855: 5854:number theory 5851: 5847: 5843: 5835: 5833: 5830: 5824: 5816: 5812: 5807: 5800: 5796: 5789: 5785: 5777: 5773: 5767: 5765: 5761: 5757: 5752: 5747: 5742: 5739: 5732: 5729: 5725: 5722: 5719: 5714: 5710: 5705: 5698: 5694: 5690: 5686: 5681: 5673: 5671: 5665: 5661: 5654: 5646: 5633: 5628: 5623: 5619: 5613: 5609: 5605: 5602: 5599: 5594: 5589: 5585: 5579: 5575: 5571: 5566: 5561: 5557: 5551: 5547: 5543: 5537: 5531: 5524: 5523:diagonal form 5520: 5515: 5509: 5500: 5498: 5496: 5493:then it is a 5480: 5474: 5468: 5462: 5456: 5453: 5447: 5444: 5438: 5434: 5431: 5428: 5425: 5422: 5411: 5406: 5399: 5395: 5388: 5387:into itself. 5384: 5380: 5373: 5367: 5361: 5355: 5353: 5348: 5342: 5336: 5330: 5325: 5324: 5319: 5318: 5312: 5305: 5301: 5295: 5289: 5280: 5275: 5269: 5263: 5258: 5252: 5248: 5244: 5239: 5238: 5232: 5226: 5220: 5216:Two elements 5213: 5205: 5199: 5193: 5187: 5183: 5177: 5173: 5166: 5162: 5159: 5155: 5151: 5147: 5142: 5138: 5132: 5128: 5124: 5120: 5114: 5109: 5108: 5107: 5104: 5100: 5096: 5090: 5087: 5082: 5076: 5072: 5068: 5064: 5060: 5056: 5052: 5048: 5044: 5040: 5036: 5032: 5028: 5022: 5017: 5011: 5007: 5003: 4999: 4995: 4991: 4987: 4981: 4975: 4971: 4967: 4963: 4958: 4953: 4947: 4942: 4937: 4928: 4926: 4923: 4917: 4911: 4905: 4899: 4886: 4883: 4880: 4877: 4866: 4863: 4856: 4853: 4849: 4843: 4837: 4829: 4823: 4819: 4815: 4810: 4804: 4800: 4792: 4788: 4781: 4775: 4772: 4766: 4760: 4755: 4750: 4744: 4738: 4732: 4726: 4719: 4715: 4708: 4704: 4700: 4696: 4692: 4688: 4681: 4675: 4668: 4664: 4660: 4653: 4646: 4642: 4635: 4631: 4627: 4623: 4619: 4615: 4611: 4607: 4603: 4599: 4594: 4589: 4583: 4580: 4574: 4567: 4563: 4559: 4555: 4551: 4545: 4539: 4533: 4527: 4520: 4516: 4512: 4508: 4504: 4500: 4494: 4477: 4468: 4462: 4459: 4453: 4447: 4444: 4438: 4435: 4432: 4426: 4417: 4414: 4408: 4402: 4399: 4396: 4390: 4381: 4375: 4371: 4367: 4363: 4357: 4351: 4338: 4332: 4326: 4321: 4317: 4313: 4307: 4304: 4298: 4289: 4283: 4277: 4271: 4266: 4261: 4255: 4253: 4248: 4245: 4239: 4234: 4229: 4216: 4211: 4207: 4203: 4195: 4191: 4187: 4184: 4181: 4176: 4172: 4150: 4146: 4142: 4139: 4136: 4131: 4127: 4117: 4114: 4106: 4102: 4098: 4095: 4092: 4087: 4083: 4076: 4068: 4063: 4059: 4052: 4048: 4042: 4038: 4032: 4026: 4022: 4018: 4014: 4009: 4004: 3999: 3995:over a field 3993: 3989: 3986:-dimensional 3984: 3977: 3969: 3967: 3964: 3947: 3941: 3938: 3935: 3929: 3926: 3920: 3914: 3905: 3899: 3893: 3888: 3882: 3878: 3872: 3859: 3856: 3853: 3842: 3838: 3835: 3832: 3821: 3817: 3808: 3802: 3799: 3793: 3787: 3784: 3778: 3775: 3772: 3766: 3757: 3754: 3748: 3742: 3739: 3736: 3728: 3724: 3714: 3709: 3704: 3691: 3688: 3685: 3674: 3670: 3667: 3658: 3652: 3646: 3640: 3634: 3628: 3622: 3615: 3611: 3606: 3601: 3595: 3589: 3584: 3579: 3566: 3560: 3557: 3551: 3548: 3542: 3536: 3526: 3522: 3518: 3514: 3509: 3504: 3498: 3492: 3486: 3480: 3476: 3472: 3467: 3460: 3456: 3449: 3445: 3439: 3426: 3423: 3420: 3409: 3405: 3399: 3393: 3384: 3378: 3372: 3368: 3360: 3356: 3352: 3345: 3341: 3332: 3327: 3326:column vector 3322: 3316: 3303: 3300: 3297: 3292: 3289: 3285: 3280: 3274: 3270: 3262: 3258: 3251: 3248: 3244: 3238: 3233: 3230: 3227: 3223: 3217: 3212: 3209: 3206: 3202: 3198: 3190: 3186: 3182: 3179: 3176: 3171: 3167: 3160: 3151: 3145: 3140: 3135: 3131:over a field 3130: 3125: 3119: 3118:is bilinear. 3115: 3111: 3107: 3103: 3099: 3095: 3091: 3085: 3081: 3075: 3071: 3064: 3060: 3057: 3053: 3049: 3043: 3037: 3031: 3027: 3023: 3017: 3013:over a field 3012: 3004: 3002: 3000: 2996: 2990: 2986: 2982: 2978: 2971: 2964: 2957: 2953: 2948: 2942: 2936: 2935: 2930: 2926: 2921: 2915: 2910: 2905: 2898: 2894: 2888: 2881: 2877: 2870: 2866: 2860: 2854: 2851: 2845: 2840: 2837: 2833: 2825: 2816: 2810: 2801: 2792: 2783: 2777: 2771: 2765: 2759: 2740: 2732: 2728: 2722: 2717: 2712: 2705: 2700: 2695: 2690: 2683: 2678: 2671: 2667: 2661: 2654: 2649: 2644: 2637: 2633: 2626: 2621: 2618: 2609: 2603: 2590: 2587: 2584: 2573: 2569: 2566: 2560: 2551: 2545: 2539: 2535: 2531: 2527: 2521: 2515: 2510: 2494: 2491: 2488: 2477: 2473: 2467: 2461: 2452: 2448: 2442: 2436: 2430: 2425: 2422:-dimensional 2420: 2414: 2408: 2405: 2397: 2393: 2388: 2383: 2381: 2376: 2370: 2364: 2357: 2353: 2347: 2345: 2339: 2335: 2332:nondegenerate 2327: 2323: 2322: 2315: 2311: 2305: 2298: 2291: 2284: 2278: 2274: 2270: 2264: 2260: 2255: 2250: 2248: 2244: 2238: 2234: 2227: 2220: 2215: 2199: 2194: 2189: 2179: 2170: 2166: 2162: 2159: 2156: 2151: 2146: 2136: 2127: 2123: 2119: 2114: 2109: 2099: 2090: 2086: 2077: 2076:diagonal form 2073: 2069: 2065: 2061: 2059: 2053: 2049: 2045: 2037: 2035: 2033: 2029: 2025: 2021: 2016: 2012: 2008: 1999: 1982: 1977: 1971: 1968: 1964: 1960: 1955: 1952: 1948: 1941: 1937: 1934: 1927:, the matrix 1923: 1919: 1915: 1908: 1904: 1895: 1893: 1890: 1877: 1872: 1866: 1859: 1855: 1852: 1849: 1839: 1835: 1832: 1829: 1817: 1813: 1810: 1807: 1799: 1792: 1788: 1785: 1782: 1770: 1766: 1763: 1760: 1750: 1746: 1743: 1740: 1732: 1726: 1721: 1718: 1711: 1705: 1701: 1695: 1691: 1685: 1681: 1675: 1671: 1665: 1652: 1649: 1646: 1640: 1637: 1634: 1628: 1625: 1622: 1616: 1613: 1610: 1604: 1601: 1598: 1592: 1589: 1586: 1580: 1575: 1571: 1567: 1564: 1559: 1555: 1551: 1548: 1543: 1539: 1535: 1532: 1526: 1523: 1520: 1517: 1514: 1506: 1502: 1492: 1479: 1474: 1468: 1463: 1458: 1451: 1446: 1441: 1434: 1429: 1424: 1418: 1413: 1410: 1403:has the form 1399:. The matrix 1397: 1393: 1389: 1380: 1378: 1373: 1369: 1365: 1348: 1340: 1323: 1317: 1313: 1305: 1301: 1294: 1291: 1287: 1281: 1276: 1273: 1270: 1266: 1260: 1255: 1252: 1249: 1245: 1241: 1233: 1229: 1225: 1222: 1219: 1214: 1210: 1201: 1197: 1189:variables by 1187: 1180: 1176: 1170: 1164: 1160: 1151: 1149: 1147: 1146:modular group 1143: 1139: 1135: 1131: 1129: 1124: 1119: 1117: 1113: 1109: 1103: 1099: 1094: 1089: 1085: 1081: 1076: 1075: 1070: 1065: 1063: 1058: 1052: 1046: 1042: 1037: 1029: 1027: 1025: 1024: 1019: 1014: 1010: 1006: 1000: 996:over a field 995: 990: 983: 979: 973: 968: 955: 950: 946: 942: 937: 933: 929: 924: 920: 916: 911: 899: 896: 893: 890: 887: 875: 870: 859: 856: 853: 850: 847: 841: 835: 832: 829: 826: 823: 814: 811: 805: 802: 799: 796: 793: 787: 777: 773: 769: 763: 759: 755: 751: 747: 743: 739: 736:-dimensional 733: 727: 724:-dimensional 721: 714: 709: 704: 702: 697: 692: 691:modular forms 688: 684: 680: 679:number theory 676: 670: 666: 662: 659: 652: 647: 643: 639: 635: 631: 627: 623: 619: 614: 612: 607: 601: 595: 568: 565: 562: 559: 554: 550: 546: 543: 540: 537: 534: 531: 526: 522: 518: 515: 512: 509: 506: 503: 498: 494: 490: 487: 485: 477: 474: 471: 468: 465: 459: 440: 436: 432: 429: 426: 423: 420: 417: 412: 408: 404: 401: 399: 391: 388: 385: 379: 360: 356: 352: 349: 347: 339: 333: 321: 317: 316: 311: 306: 297: 295: 293: 289: 284: 263: 260: 236: 228: 224: 220: 216: 212: 209:, especially 208: 204: 200: 196: 192: 188: 184: 180: 176: 172: 171:number theory 167: 165: 161: 156: 152: 143: 139: 132: 119: 104: 100: 96: 93: 90: 87: 84: 81: 76: 72: 68: 60: 56: 52: 48: 44: 40: 33: 19: 6968: 6950: 6906: 6870: 6832: 6786: 6756: 6725: 6691: 6669: 6644: 6622: 6616: 6609:, p. 27 6606: 6595: 6586: 6577: 6571: 6556: 6548: 6537: 6526: 6506: 6497: 6491: 6485: 6483:in place of 6479: 6472: 6465: 6458: 6456:in place of 6452: 6441: 6417:Square class 6384: 6367:{1, 2, 5, 5} 6364: 6356: 6352: 6343: 6339: 6330: 6326: 6317: 6313: 6304: 6300: 6291: 6287: 6278: 6274: 6262: 6258: 6254: 6250: 6243: 6239: 6235: 6231: 6221: 6217: 6213: 6209: 6200: 6198: 6154: 6152: 6075: 6071: 6067: 6064: 6057: 5995: 5991: 5987: 5984: 5980: 5972: 5964: 5957: 5955: 5947: 5940: 5936: 5930: 5926: 5922: 5918: 5906: 5905:is integral 5901: 5895: 5889: 5883: 5873: 5869: 5865: 5862: 5845: 5841: 5839: 5828: 5822: 5814: 5810: 5798: 5794: 5787: 5783: 5775: 5771: 5768: 5763: 5750: 5743: 5737: 5730: 5727: 5723: 5720: 5717: 5713:solution set 5703: 5696: 5692: 5688: 5684: 5677: 5663: 5659: 5652: 5647: 5522: 5513: 5507: 5504: 5404: 5397: 5393: 5389: 5382: 5378: 5371: 5365: 5359: 5356: 5351: 5346: 5340: 5334: 5328: 5321: 5315: 5310: 5303: 5299: 5293: 5287: 5279:non-singular 5278: 5273: 5267: 5261: 5256: 5250: 5246: 5242: 5235: 5230: 5224: 5218: 5215: 5197: 5191: 5185: 5181: 5175: 5171: 5164: 5160: 5157: 5153: 5149: 5140: 5136: 5130: 5126: 5122: 5118: 5112: 5102: 5098: 5094: 5091: 5085: 5080: 5074: 5070: 5066: 5062: 5058: 5054: 5050: 5046: 5042: 5038: 5034: 5030: 5026: 5020: 5015: 5009: 5005: 5001: 4997: 4993: 4989: 4985: 4979: 4973: 4969: 4965: 4961: 4951: 4945: 4935: 4932: 4921: 4915: 4909: 4903: 4900: 4830:) such that 4827: 4821: 4817: 4813: 4808: 4802: 4798: 4790: 4786: 4779: 4776: 4770: 4764: 4758: 4753: 4752:is called a 4748: 4742: 4736: 4730: 4724: 4717: 4713: 4709: 4702: 4698: 4694: 4690: 4686: 4679: 4673: 4666: 4662: 4658: 4651: 4644: 4640: 4633: 4629: 4625: 4621: 4617: 4613: 4609: 4605: 4601: 4597: 4587: 4584: 4578: 4572: 4565: 4561: 4557: 4553: 4549: 4543: 4537: 4531: 4525: 4518: 4514: 4510: 4506: 4502: 4498: 4492: 4383:is defined: 4379: 4373: 4369: 4365: 4361: 4355: 4352: 4287: 4281: 4275: 4269: 4259: 4256: 4251: 4249: 4243: 4237: 4230: 4061: 4057: 4050: 4046: 4040: 4036: 4030: 4024: 4020: 4016: 4007: 4002: 3997: 3991: 3988:vector space 3982: 3979: 3962: 3903: 3897: 3895:with matrix 3891: 3880: 3876: 3873: 3712: 3707: 3705: 3656: 3650: 3644: 3638: 3632: 3626: 3620: 3613: 3609: 3599: 3593: 3587: 3580: 3524: 3520: 3512: 3507: 3502: 3496: 3490: 3484: 3481: 3474: 3470: 3458: 3454: 3447: 3443: 3440: 3382: 3376: 3374:matrix over 3370: 3366: 3358: 3354: 3350: 3343: 3339: 3330: 3320: 3317: 3149: 3143: 3133: 3128: 3123: 3120: 3113: 3109: 3105: 3101: 3097: 3093: 3089: 3083: 3079: 3073: 3069: 3062: 3058: 3055: 3051: 3047: 3041: 3035: 3029: 3025: 3021: 3015: 3010: 3008: 2988: 2984: 2980: 2976: 2969: 2962: 2955: 2951: 2940: 2932: 2924: 2919: 2913: 2903: 2896: 2892: 2886: 2879: 2875: 2868: 2864: 2858: 2855: 2849: 2843: 2838: 2835: 2831: 2823: 2814: 2808: 2799: 2790: 2781: 2775: 2769: 2763: 2757: 2607: 2604: 2549: 2543: 2537: 2529: 2525: 2519: 2513: 2508: 2450: 2446: 2440: 2434: 2428: 2418: 2412: 2409: 2406: 2395: 2391: 2384: 2374: 2368: 2362: 2355: 2351: 2343: 2329: 2325: 2319: 2313: 2309: 2306: 2296: 2289: 2282: 2276: 2262: 2258: 2251: 2236: 2232: 2225: 2218: 2062: 2055: 2017: 2010: 2006: 1921: 1917: 1913: 1906: 1902: 1899: 1896:General case 1891: 1703: 1699: 1693: 1689: 1683: 1679: 1673: 1669: 1666: 1493: 1395: 1391: 1387: 1384: 1371: 1367: 1363: 1185: 1178: 1174: 1168: 1162: 1158: 1155: 1126: 1120: 1101: 1097: 1087: 1083: 1079: 1072: 1066: 1056: 1050: 1044: 1040: 1033: 1021: 1017: 1012: 1008: 1004: 998: 994:vector space 988: 981: 977: 971: 969: 775: 771: 767: 731: 719: 712: 705: 695: 668: 664: 657: 650: 615: 611:coefficients 610: 605: 599: 596: 319: 313: 309: 304: 301: 298:Introduction 285: 219:Killing form 179:group theory 168: 154: 150: 120: 42: 36: 6511:away from 2 6207:shows that 5760:hyperboloid 5746:eigenvalues 5234:are called 4638:. However, 4069:, one has 3466:null vector 3005:Definitions 2997:(and hence 2797:for 1, and 2324:(all 1) or 2247:permutation 1069:Brahmagupta 39:mathematics 6985:Categories 6931:0847.11014 6893:0259.10018 6859:0292.10016 6829:Milnor, J. 6821:1068.11023 6775:0785.11021 6748:0395.10029 6634:References 6565:HathiTrust 6422:Witt group 6392:Cubic form 6351:{1, 2, 5, 6338:{1, 2, 4, 6325:{1, 2, 3, 6312:{1, 2, 2, 6299:{1, 1, 3, 6286:{1, 1, 2, 6273:{1, 1, 1, 5916:, meaning 5806:paraboloid 5701:, and let 5519:equivalent 5297:such that 5237:orthogonal 5210:See also: 5201:-bilinear. 5134:such that 5081:polar form 3974:See also: 3529:such that 3508:equivalent 3045:such that 2999:pin groups 2360:(denoting 2273:invariants 2042:See also: 1125:published 223:statistics 215:Lie theory 47:polynomial 6975:EMS Press 6957:EMS Press 6227:Ramanujan 6201:universal 6184:Lie group 5756:ellipsoid 5709:symmetric 5603:⋯ 5432:∈ 5420:∀ 5317:isotropic 5041: : ( 4881:∈ 4809:isometric 4710:The pair 4460:− 4445:− 4204:∈ 4185:… 4140:… 4096:… 4065:with its 3980:Given an 3800:− 3785:− 3552:φ 3537:ψ 3441:A vector 3298:∈ 3224:∑ 3203:∑ 3180:… 3019:is a map 2729:λ 2723:⋯ 2701:⋱ 2696:⋮ 2691:⋮ 2679:⋯ 2668:λ 2650:⋯ 2634:λ 2564:→ 2380:spacetime 2277:signature 2183:~ 2167:λ 2160:⋯ 2140:~ 2124:λ 2103:~ 2087:λ 1998:symmetric 1267:∑ 1246:∑ 1223:… 1136:over the 1108:Brouncker 577:(ternary) 261:− 256:Σ 237:− 207:manifolds 94:− 6903:(1995). 6869:(1973). 6785:(2005). 6724:(1978). 6697:Springer 6643:(2000), 6517:(by the 6378:See also 6190:aspects. 6173:topology 6155:twos out 6056:uses in 5973:twos out 5858:topology 5850:lattices 5667:⟩ 5651:⟨ 5323:definite 5169:for all 5121: : 5097: : 5029: : 4996: : 4988: : 4964: : 4857:′ 4828:isometry 4816: : 4671:for all 4570:for all 4523:for all 4364: : 4257:The map 4019: : 4013:function 3581:Let the 3067:for all 3024: : 2882:) < 0 2871:) > 0 2836:negative 2832:positive 2344:bilinear 2214:diagonal 1138:integers 1121:In 1801 1116:Lagrange 1048:, where 1007: : 907:‖ 881:‖ 762:distance 752:and the 630:integers 609:are the 451:(binary) 6813:2104929 6407:Quadric 6355:}, 6 ≤ 6342:}, 4 ≤ 6329:}, 3 ≤ 6316:}, 2 ≤ 6303:}, 3 ≤ 6290:}, 2 ≤ 6277:}, 1 ≤ 6166:lattice 5965:twos in 5744:If all 5658:, ..., 5079:is the 5014:is the 3453:, ..., 3386:. Then 3364:be the 3337:, ..., 3324:be the 2934:compact 2890:. When 2788:for 0, 2366:1s and 2231:, ..., 1381:Example 1166:matrix 1030:History 986:, with 756:of the 728:in the 726:quadric 654:or the 603:, ..., 371:(unary) 320:ternary 221:), and 142:complex 6929:  6919:  6891:  6881:  6857:  6847:  6819:  6811:  6801:  6773:  6763:  6746:  6736:  6703:  6676:  6655:  5678:Using 5408:is an 5257:kernel 5255:. The 5024:, and 4977:be an 4959:, and 4957:module 4949:be an 4756:, and 3874:Thus, 2983:) ≈ O( 2907:is an 2507:where 2064:Jacobi 2050:, and 1361:where 1144:, the 1071:wrote 1020:. See 1002:, and 754:square 706:Using 689:, and 597:where 318:, and 315:binary 193:, the 53:two (" 51:degree 6447:Gauss 6433:Notes 6054:Gauss 5758:or a 5707:be a 5521:to a 5306:) = 0 5253:) = 0 4939:be a 4740:from 4728:over 4669:) = 0 4377:over 4263:is a 4011:is a 3889:over 3885:is a 3500:over 3477:) = 0 3464:is a 3137:is a 3127:-ary 2931:is a 2243:up to 2020:field 1123:Gauss 1112:Euler 642:field 632:. In 628:, or 310:unary 217:(the 189:(the 148:. If 131:field 45:is a 6917:ISBN 6879:ISBN 6845:ISBN 6799:ISBN 6761:ISBN 6734:ISBN 6701:ISBN 6674:ISBN 6653:ISBN 6563:via 6359:≤ 10 6346:≤ 14 6333:≤ 10 6294:≤ 14 6186:and 6182:the 6175:for 6164:the 5929:) ∈ 5856:and 5222:and 5179:and 5156:) = 5069:) − 5061:) − 5049:) ↦ 4933:Let 4807:are 4795:and 4777:Two 4697:) = 4628:) − 4620:) − 4608:) = 4593:unit 4556:) = 4509:) = 4279:and 4231:The 4001:, a 3706:The 3506:are 3494:and 3482:Two 3348:and 3108:) − 3100:) − 3054:) = 2966:and 2834:and 2821:and 2424:real 2410:Let 2402:(−1) 2385:The 2346:form 1687:and 1156:Any 1114:and 734:− 1) 722:− 2) 618:real 138:real 125:and 55:form 41:, a 6927:Zbl 6889:Zbl 6855:Zbl 6817:Zbl 6771:Zbl 6744:Zbl 6320:≤ 7 6307:≤ 6 6281:≤ 7 6203:. 6072:bxy 5992:bxy 5990:+ 2 5943:∈ Λ 5934:if 5893:or 5818:= 0 5802:≠ 0 5779:= 0 5748:of 5733:= 1 5687:= ( 5511:in 5350:is 5338:of 5314:is 5291:in 5283:{0} 5277:is 5240:if 5228:of 5195:is 5083:of 5018:of 4801:′, 4746:to 4576:in 4535:in 4285:in 4273:in 4164:for 4044:to 4005:on 3654:of 3642:of 3616:)/2 3597:of 3585:of 3468:if 3446:= ( 3353:= ( 2925:one 2394:/ ( 2022:of 1996:is 1916:= ( 1366:= ( 1183:in 1104:= 1 620:or 283:) 213:), 205:of 197:), 185:), 140:or 37:In 6987:: 6973:, 6967:, 6955:, 6949:, 6925:. 6915:. 6887:. 6877:. 6853:. 6843:. 6835:. 6815:. 6809:MR 6807:. 6797:. 6789:. 6769:. 6742:. 6732:. 6699:. 6695:. 6651:, 6603:– 6559:, 6495:, 6489:, 6476:, 6469:, 6261:, 6257:, 6253:, 6244:dz 6242:+ 6240:cy 6238:+ 6236:bx 6234:+ 6232:aw 6220:+ 6216:+ 6212:+ 6076:cy 6074:+ 6070:+ 6068:ax 6062:. 5996:cy 5994:+ 5988:ax 5945:. 5939:, 5925:, 5872:+ 5870:xy 5868:+ 5860:. 5741:. 5726:+ 5695:, 5691:, 5497:. 5396:, 5381:, 5354:. 5271:. 5249:, 5184:∈ 5174:∈ 5154:av 5129:→ 5125:× 5101:→ 5089:. 5057:+ 5045:, 5037:→ 5033:× 5008:, 5000:↦ 4992:→ 4972:→ 4968:× 4943:, 4925:. 4820:→ 4805:′) 4789:, 4716:, 4707:. 4693:, 4689:″( 4665:, 4661:′( 4616:+ 4604:, 4600:′( 4582:. 4564:, 4547:: 4529:, 4517:, 4505:, 4372:→ 4368:× 4291:: 4254:. 4060:= 4039:∈ 4023:→ 3612:+ 3523:, 3517:GL 3515:∈ 3479:. 3369:× 3359:ij 3153:: 3096:+ 3082:∈ 3077:, 3072:∈ 3052:av 3028:→ 3009:A 2991:)) 2987:, 2979:, 2975:O( 2954:, 2950:O( 2939:O( 2853:. 2528:× 2449:× 2404:. 2382:. 2354:, 2295:, 2288:, 2249:. 2245:a 2224:, 2078:" 2060:. 2046:, 2015:. 1922:ij 1692:+ 1682:+ 1677:, 1672:+ 1394:, 1390:, 1377:. 1372:ij 1161:× 1118:. 1110:, 1102:ny 1100:− 1095:, 1086:= 1084:ny 1082:− 1054:, 1043:+ 1011:→ 992:a 980:, 774:, 770:, 703:. 685:, 673:. 636:, 624:, 613:. 312:, 294:. 177:, 173:, 166:. 153:= 6933:. 6895:. 6861:. 6823:. 6777:. 6750:. 6709:. 6626:. 6623:R 6611:. 6578:q 6498:f 6492:d 6486:b 6480:f 6478:2 6473:d 6471:2 6466:b 6464:2 6459:b 6453:b 6451:2 6385:ε 6357:d 6353:d 6344:d 6340:d 6331:d 6327:d 6318:d 6314:d 6305:d 6301:d 6292:d 6288:d 6279:d 6275:d 6265:} 6263:d 6259:c 6255:b 6251:a 6249:{ 6222:z 6218:y 6214:x 6210:w 6179:; 6139:. 6134:) 6128:c 6123:2 6119:/ 6115:b 6108:2 6104:/ 6100:b 6095:a 6089:( 6038:) 6032:c 6027:b 6020:b 6015:a 6009:( 5941:y 5937:x 5931:Z 5927:y 5923:x 5921:( 5919:Q 5914:Λ 5910:Λ 5902:Q 5896:R 5890:Q 5884:V 5879:Λ 5874:y 5866:x 5829:b 5823:i 5815:i 5811:b 5799:i 5795:b 5788:i 5784:b 5776:i 5772:λ 5751:A 5738:A 5731:x 5728:b 5724:x 5721:A 5718:x 5704:A 5699:) 5697:z 5693:y 5689:x 5685:x 5664:n 5660:a 5656:1 5653:a 5634:. 5629:2 5624:n 5620:x 5614:n 5610:a 5606:+ 5600:+ 5595:2 5590:2 5586:x 5580:2 5576:a 5572:+ 5567:2 5562:1 5558:x 5552:1 5548:a 5544:= 5541:) 5538:x 5535:( 5532:q 5514:n 5508:q 5481:, 5478:) 5475:y 5472:( 5469:Q 5466:) 5463:x 5460:( 5457:Q 5454:= 5451:) 5448:y 5445:x 5442:( 5439:Q 5435:A 5429:y 5426:, 5423:x 5405:A 5400:) 5398:Q 5394:A 5392:( 5385:) 5383:Q 5379:V 5377:( 5372:Q 5366:V 5360:Q 5347:U 5341:V 5335:U 5329:Q 5311:Q 5304:v 5302:( 5300:Q 5294:V 5288:v 5274:Q 5268:V 5262:B 5251:w 5247:v 5245:( 5243:B 5231:V 5225:w 5219:v 5198:R 5192:q 5186:M 5182:v 5176:R 5172:a 5167:) 5165:v 5163:( 5161:q 5158:a 5152:( 5150:q 5143:) 5141:v 5139:( 5137:q 5131:R 5127:M 5123:M 5119:b 5113:R 5103:R 5099:M 5095:q 5086:q 5077:) 5075:v 5073:( 5071:q 5067:u 5065:( 5063:q 5059:v 5055:u 5053:( 5051:q 5047:v 5043:u 5039:R 5035:M 5031:M 5027:B 5021:b 5012:) 5010:v 5006:v 5004:( 5002:b 4998:v 4994:R 4990:M 4986:q 4980:R 4974:R 4970:M 4966:M 4962:b 4955:- 4952:R 4946:M 4936:R 4922:K 4916:n 4910:K 4904:n 4887:. 4884:V 4878:v 4870:) 4867:v 4864:T 4861:( 4854:Q 4850:= 4847:) 4844:v 4841:( 4838:Q 4826:( 4824:′ 4822:V 4818:V 4814:T 4803:Q 4799:V 4797:( 4793:) 4791:Q 4787:V 4785:( 4780:n 4771:Q 4765:Q 4759:B 4749:K 4743:V 4737:Q 4731:K 4725:V 4720:) 4718:Q 4714:V 4712:( 4705:) 4703:x 4701:( 4699:Q 4695:x 4691:x 4687:B 4682:″ 4680:B 4674:x 4667:x 4663:x 4659:B 4654:′ 4652:B 4647:) 4645:x 4643:( 4641:Q 4636:) 4634:y 4632:( 4630:Q 4626:x 4624:( 4622:Q 4618:y 4614:x 4612:( 4610:Q 4606:y 4602:x 4598:B 4588:K 4579:V 4573:x 4568:) 4566:x 4562:x 4560:( 4558:B 4554:x 4552:( 4550:Q 4544:Q 4538:V 4532:y 4526:x 4521:) 4519:x 4515:y 4513:( 4511:B 4507:y 4503:x 4501:( 4499:B 4493:B 4478:. 4475:) 4472:) 4469:w 4466:( 4463:Q 4457:) 4454:v 4451:( 4448:Q 4442:) 4439:w 4436:+ 4433:v 4430:( 4427:Q 4424:( 4418:2 4415:1 4409:= 4406:) 4403:w 4400:, 4397:v 4394:( 4391:B 4380:K 4374:K 4370:V 4366:V 4362:B 4356:K 4339:. 4336:) 4333:v 4330:( 4327:Q 4322:2 4318:a 4314:= 4311:) 4308:v 4305:a 4302:( 4299:Q 4288:V 4282:v 4276:K 4270:a 4260:Q 4244:q 4238:V 4217:. 4212:n 4208:K 4201:] 4196:n 4192:v 4188:, 4182:, 4177:1 4173:v 4169:[ 4159:) 4156:] 4151:n 4147:v 4143:, 4137:, 4132:1 4128:v 4124:[ 4121:( 4118:Q 4115:= 4112:) 4107:n 4103:v 4099:, 4093:, 4088:1 4084:v 4080:( 4077:q 4062:K 4058:V 4053:) 4051:v 4049:( 4047:Q 4041:V 4037:v 4031:q 4025:K 4021:V 4017:Q 4008:V 3998:K 3992:V 3983:n 3963:n 3948:, 3945:) 3942:x 3939:, 3936:x 3933:( 3930:b 3927:= 3924:) 3921:x 3918:( 3915:q 3904:b 3898:A 3892:K 3881:q 3877:b 3860:. 3857:x 3854:A 3848:T 3843:y 3839:= 3836:y 3833:A 3827:T 3822:x 3818:= 3815:) 3812:) 3809:y 3806:( 3803:q 3797:) 3794:x 3791:( 3788:q 3782:) 3779:y 3776:+ 3773:x 3770:( 3767:q 3764:( 3758:2 3755:1 3749:= 3746:) 3743:y 3740:, 3737:x 3734:( 3729:q 3725:b 3713:q 3692:. 3689:C 3686:A 3680:T 3675:C 3671:= 3668:B 3657:ψ 3651:B 3645:φ 3639:A 3633:C 3627:A 3621:A 3614:A 3610:A 3608:( 3600:q 3594:A 3588:K 3567:. 3564:) 3561:x 3558:C 3555:( 3549:= 3546:) 3543:x 3540:( 3527:) 3525:K 3521:n 3519:( 3513:C 3503:K 3497:ψ 3491:φ 3485:n 3475:v 3473:( 3471:q 3462:) 3459:n 3455:x 3451:1 3448:x 3444:v 3427:. 3424:x 3421:A 3415:T 3410:x 3406:= 3403:) 3400:x 3397:( 3394:q 3383:q 3377:K 3371:n 3367:n 3362:) 3355:a 3351:A 3344:n 3340:x 3334:1 3331:x 3321:x 3304:. 3301:K 3293:j 3290:i 3286:a 3281:, 3275:j 3271:x 3263:i 3259:x 3252:j 3249:i 3245:a 3239:n 3234:1 3231:= 3228:j 3218:n 3213:1 3210:= 3207:i 3199:= 3196:) 3191:n 3187:x 3183:, 3177:, 3172:1 3168:x 3164:( 3161:q 3150:K 3144:n 3134:K 3124:n 3116:) 3114:v 3112:( 3110:q 3106:u 3104:( 3102:q 3098:v 3094:u 3092:( 3090:q 3084:V 3080:v 3074:K 3070:a 3065:) 3063:v 3061:( 3059:q 3056:a 3050:( 3048:q 3042:K 3036:K 3030:K 3026:V 3022:q 3016:K 2989:p 2985:q 2981:q 2977:p 2970:Q 2968:− 2963:Q 2958:) 2956:q 2952:p 2943:) 2941:n 2920:n 2914:n 2904:q 2899:) 2897:v 2895:( 2893:q 2887:v 2880:v 2878:( 2876:q 2869:v 2867:( 2865:q 2859:q 2850:q 2844:A 2827:− 2824:n 2818:+ 2815:n 2809:A 2803:− 2800:n 2794:+ 2791:n 2785:0 2782:n 2776:B 2770:S 2764:B 2758:S 2741:) 2733:n 2718:0 2713:0 2706:0 2684:0 2672:2 2662:0 2655:0 2645:0 2638:1 2627:( 2622:= 2619:B 2608:A 2591:. 2588:S 2585:A 2579:T 2574:S 2570:= 2567:B 2561:A 2550:B 2544:A 2538:S 2530:n 2526:n 2520:x 2514:v 2509:x 2495:, 2492:x 2489:A 2483:T 2478:x 2474:= 2471:) 2468:v 2465:( 2462:q 2451:n 2447:n 2441:A 2435:q 2429:A 2419:n 2413:q 2398:) 2396:K 2392:K 2375:R 2369:q 2363:p 2358:) 2356:q 2352:p 2350:( 2314:i 2310:λ 2302:) 2300:− 2297:n 2293:+ 2290:n 2286:0 2283:n 2281:( 2263:i 2259:λ 2237:n 2233:λ 2229:2 2226:λ 2222:1 2219:λ 2200:, 2195:2 2190:n 2180:x 2171:n 2163:+ 2157:+ 2152:2 2147:2 2137:x 2128:2 2120:+ 2115:2 2110:1 2100:x 2091:1 2011:A 2007:q 2002:A 1983:) 1978:2 1972:i 1969:j 1965:a 1961:+ 1956:j 1953:i 1949:a 1942:( 1938:= 1935:B 1925:) 1918:a 1914:A 1907:A 1903:q 1878:. 1873:] 1867:k 1860:2 1856:h 1853:+ 1850:f 1840:2 1836:g 1833:+ 1830:c 1818:2 1814:h 1811:+ 1808:f 1800:e 1793:2 1789:d 1786:+ 1783:b 1771:2 1767:g 1764:+ 1761:c 1751:2 1747:d 1744:+ 1741:b 1733:a 1727:[ 1722:= 1719:A 1704:A 1700:q 1694:h 1690:f 1684:g 1680:c 1674:d 1670:b 1653:. 1650:z 1647:y 1644:) 1641:h 1638:+ 1635:f 1632:( 1629:+ 1626:z 1623:x 1620:) 1617:g 1614:+ 1611:c 1608:( 1605:+ 1602:y 1599:x 1596:) 1593:d 1590:+ 1587:b 1584:( 1581:+ 1576:2 1572:z 1568:k 1565:+ 1560:2 1556:y 1552:e 1549:+ 1544:2 1540:x 1536:a 1533:= 1530:) 1527:z 1524:, 1521:y 1518:, 1515:x 1512:( 1507:A 1503:q 1480:. 1475:] 1469:k 1464:h 1459:g 1452:f 1447:e 1442:d 1435:c 1430:b 1425:a 1419:[ 1414:= 1411:A 1401:A 1396:z 1392:y 1388:x 1375:) 1368:a 1364:A 1349:, 1345:x 1341:A 1335:T 1329:x 1324:= 1318:j 1314:x 1306:i 1302:x 1295:j 1292:i 1288:a 1282:n 1277:1 1274:= 1271:j 1261:n 1256:1 1253:= 1250:i 1242:= 1239:) 1234:n 1230:x 1226:, 1220:, 1215:1 1211:x 1207:( 1202:A 1198:q 1186:n 1179:A 1175:q 1169:A 1163:n 1159:n 1130:, 1098:x 1088:c 1080:x 1057:y 1051:x 1045:y 1041:x 1018:V 1013:K 1009:V 1005:q 999:K 989:V 984:) 982:q 978:V 976:( 956:. 951:2 947:z 943:+ 938:2 934:y 930:+ 925:2 921:x 917:= 912:2 903:) 900:z 897:, 894:y 891:, 888:x 885:( 876:= 871:2 867:) 863:) 860:0 857:, 854:0 851:, 848:0 845:( 842:, 839:) 836:z 833:, 830:y 827:, 824:x 821:( 818:( 815:d 812:= 809:) 806:z 803:, 800:y 797:, 794:x 791:( 788:q 778:) 776:z 772:y 768:x 766:( 732:n 730:( 720:n 718:( 713:n 696:n 669:p 665:Z 658:p 651:Z 606:f 600:a 569:z 566:x 563:f 560:+ 555:2 551:z 547:e 544:+ 541:z 538:y 535:d 532:+ 527:2 523:y 519:c 516:+ 513:y 510:x 507:b 504:+ 499:2 495:x 491:a 488:= 481:) 478:z 475:, 472:y 469:, 466:x 463:( 460:q 441:2 437:y 433:c 430:+ 427:y 424:x 421:b 418:+ 413:2 409:x 405:a 402:= 395:) 392:y 389:, 386:x 383:( 380:q 361:2 357:x 353:a 350:= 343:) 340:x 337:( 334:q 305:n 270:x 264:1 248:T 242:x 201:( 181:( 155:R 151:K 146:K 134:K 127:y 123:x 105:2 101:y 97:3 91:y 88:x 85:2 82:+ 77:2 73:x 69:4 34:. 20:)

Index

Isometry (quadratic forms)
Quadratic form (statistics)
mathematics
polynomial
degree
form
homogeneous polynomial
field
real
complex
definite quadratic form
isotropic quadratic form
number theory
linear algebra
group theory
orthogonal groups
differential geometry
Riemannian metric
second fundamental form
differential topology
intersection forms
manifolds
four-manifolds
Lie theory
Killing form
statistics
multivariate normal distribution
quadratic equation
homogeneous polynomials
binary

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