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Zeros and poles

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is meromorphic on the whole curve, then the number of zeros and poles is finite, and the sum of the orders of the poles equals the sum of the orders of the zeros. This is one of the basic facts that are involved in
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is a function that is meromorphic on the whole Riemann sphere, then it has a finite number of zeros and poles, and the sum of the orders of its poles equals the sum of the orders of its zeros.
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is meromorphic on the whole Riemann sphere, and, in this case, the sum of orders of the zeros or of the poles is the maximum of the degrees of the numerator and the denominator.
2221: 714: 1416: 1163: 306: 2293: 2253: 2098: 1012: 906: 2185: 2052: 1890: 828: 778: 744: 645: 1858: 1829: 1692: 1543: 1373: 858: 2344: 299: 958:(see the image in the infobox), which is meromorphic in the whole complex plane, and has a simple pole at every non-positive integer. The 2418: 2399: 292: 157: 1436: 1975: 1032: 502: 1708: 2428: 124: 162: 152: 2354: 544: 387: 481:, that is fundamental for the study of meromorphic functions. For example, if a function is meromorphic on the whole 2364: 2334: 490: 2479: 2129: 1906: 328: 216: 2307: 2339: 1175: 1272: 520: 332: 2374: 383: 2369: 1622: 959: 344: 340: 232: 34: 2190: 2159:
to the complex numbers. This function is holomorphic (resp. meromorphic) in a neighbourhood of a point
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is meromorphic in the whole complex plane, but not at infinity. It has poles of order 1 at
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of dimension one (over the complex numbers). The simplest examples of such curves are the
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A meromorphic function may have infinitely many zeros and poles. This is the case for the
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is meromorphic on the whole Riemann sphere. It has a pole of order 1 or simple pole at
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is also meromorphic in the whole complex plane, with a single pole of order 1 at
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and the symmetry between them, it is often useful to consider a pole of order
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if it is meromorphic in some neighbourhood of infinity (that is outside some
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has a single pole at infinity of order 1, and a single zero at the origin.
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This characterization of zeros and poles implies that zeros and poles are
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is meromorphic on the whole Riemann sphere. It has a pole of order 2 at
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A polynomial of degree 9 has a pole of order 9 at ∞, here plotted by
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The concept of zeros and poles extends naturally to functions on a
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is a function that is meromorphic in a neighbourhood of a point
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of its poles equals the sum of the multiplicities of its zeros.
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of zeros and poles being defined as a non-negative number
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is holomorphic (resp. meromorphic) in a neighbourhood of
1487:{\displaystyle \lim _{z\to \infty }{\frac {f(z)}{z^{n}}}} 2016:{\displaystyle z=2\pi ni{\text{ for }}n\in \mathbb {Z} } 1115:{\displaystyle f(z)=\sum _{k\geq -n}a_{k}(z-z_{0})^{k},} 1345:, there is no principal part), one has a zero of order 1791:{\displaystyle f(z)={\frac {z+2}{(z-5)^{2}(z+7)^{3}}}} 2269: 2229: 2193: 2173: 2071: 2033: 1978: 1909: 1866: 1837: 1808: 1711: 1671: 1625: 1521: 1439: 1389: 1351: 1275: 1178: 1135: 1035: 990: 878: 836: 809: 759: 746:(this is a consequence of the analytic property). If 725: 664: 626: 2287: 2247: 2215: 2179: 2092: 2046: 2015: 1960: 1884: 1852: 1823: 1790: 1686: 1653: 1537: 1486: 1410: 1367: 1337: 1246: 1157: 1114: 1006: 900: 852: 822: 772: 738: 708: 639: 973:is the conjecture that all other zeros are along 719:is holomorphic and nonzero in a neighbourhood of 1441: 1574:extended by a point at infinity is called the 559:has a neighbourhood such that at least one of 2114:Pole–zero plot § Continuous-time systems 872:are terms used for zeroes and poles of order 300: 8: 2433:Applied and Computational Complex Analysis 1 2108:All above examples except for the third are 1961:{\displaystyle f(z)={\frac {z-4}{e^{z}-1}}} 531:. Equivalently, it is holomorphic if it is 307: 293: 29: 2268: 2228: 2204: 2192: 2172: 2070: 2038: 2032: 2009: 2008: 1997: 1977: 1943: 1925: 1908: 1865: 1836: 1807: 1779: 1757: 1727: 1710: 1670: 1641: 1624: 1530: 1522: 1520: 1476: 1456: 1444: 1438: 1388: 1360: 1352: 1350: 1328: 1320: 1319: 1309: 1289: 1281: 1280: 1274: 1237: 1229: 1225: 1215: 1195: 1187: 1183: 1177: 1140: 1134: 1103: 1093: 1074: 1055: 1034: 995: 989: 911:is sometimes used synonymously to order. 887: 879: 877: 845: 837: 835: 814: 808: 764: 758: 730: 724: 688: 678: 663: 631: 625: 339:variable. It is the simplest type of non- 1497:exists and is a nonzero complex number. 1247:{\displaystyle a_{-|n|}(z-z_{0})^{-|n|}} 1026:(the terms with negative index values): 543:, and converges to the function in some 222: 215: 137: 99: 61: 45: 1338:{\displaystyle a_{|n|}(z-z_{0})^{|n|}} 7: 2411:Functions of One Complex Variable II 2345:Hurwitz's theorem (complex analysis) 2392:Functions of One Complex Variable I 2155:be a function from a complex curve 1654:{\displaystyle f(z)={\frac {3}{z}}} 2023:. This can be seen by writing the 1451: 25: 2216:{\displaystyle f\circ \phi ^{-1}} 1892:and a quadruple zero at infinity. 709:{\displaystyle (z-z_{0})^{n}f(z)} 473:. This induces a duality between 1258:terms), one has a pole of order 274: 53: 2325:Control theory § Stability 1014:a nonzero meromorphic function 651:, then there exists an integer 2279: 2273: 2239: 2233: 2081: 2075: 1919: 1913: 1776: 1763: 1754: 1741: 1721: 1715: 1694:and a simple zero at infinity. 1635: 1629: 1531: 1523: 1468: 1462: 1448: 1405: 1399: 1393: 1361: 1353: 1329: 1321: 1316: 1296: 1290: 1282: 1238: 1230: 1222: 1202: 1196: 1188: 1100: 1080: 1045: 1039: 984:In a neighbourhood of a point 888: 880: 846: 838: 703: 697: 685: 665: 503:function of a complex variable 1: 2259:is a pole or a zero of order 1411:{\displaystyle z\mapsto f(z)} 1158:{\displaystyle a_{-n}\neq 0.} 323:(a branch of mathematics), a 547:of the point. A function is 2355:Nyquist stability criterion 1426:), and there is an integer 425:there is a neighborhood of 27:Concept in complex analysis 2496: 2365:Residue (complex analysis) 2335:Filter (signal processing) 1860:. It has a simple zero at 579:of a meromorphic function 2288:{\displaystyle \phi (z).} 2248:{\displaystyle \phi (z).} 2130:complex analytic manifold 1831:and a pole of order 3 at 1254:, the principal part has 539:exists at every point of 429:in which at least one of 217:Geometric function theory 163:Cauchy's integral formula 153:Cauchy's integral theorem 2409:Conway, John B. (1995). 2263:if the same is true for 356:is a pole of a function 347:). Technically, a point 343:of such a function (see 125:Cauchy–Riemann equations 1420:meromorphic at infinity 333:complex-valued function 110:Complex-valued function 2289: 2249: 2217: 2181: 2094: 2093:{\displaystyle f(z)=z} 2048: 2017: 1962: 1886: 1854: 1825: 1792: 1688: 1655: 1609: 1608:of the Riemann sphere. 1539: 1515:, and a zero of order 1488: 1412: 1369: 1339: 1248: 1159: 1116: 1008: 1007:{\displaystyle z_{0},} 902: 901:{\displaystyle |n|=1.} 854: 824: 774: 740: 710: 641: 570:is holomorphic in it. 489:, then the sum of the 384:complex differentiable 281:Mathematics portal 2437:John Wiley & Sons 2290: 2250: 2218: 2182: 2180:{\displaystyle \phi } 2144:, which are analytic 2095: 2049: 2047:{\displaystyle e^{z}} 2018: 1963: 1887: 1885:{\displaystyle z=-2,} 1855: 1826: 1793: 1689: 1656: 1603: 1563:has a pole of degree 1540: 1489: 1413: 1370: 1340: 1269:(the sum starts with 1249: 1172:(the sum starts with 1160: 1117: 1009: 960:Riemann zeta function 903: 855: 825: 823:{\displaystyle z_{0}} 775: 773:{\displaystyle z_{0}} 741: 739:{\displaystyle z_{0}} 711: 642: 640:{\displaystyle z_{0}} 345:essential singularity 341:removable singularity 327:is a certain type of 233:Augustin-Louis Cauchy 35:Mathematical analysis 2308:Riemann–Roch theorem 2267: 2227: 2191: 2171: 2167:if there is a chart 2151:More precisely, let 2069: 2031: 1976: 1907: 1864: 1853:{\displaystyle z=-7} 1835: 1824:{\displaystyle z=5,} 1806: 1709: 1687:{\displaystyle z=0,} 1669: 1623: 1519: 1437: 1387: 1349: 1273: 1176: 1133: 1033: 1022:with at most finite 988: 940:and a zero of order 876: 834: 807: 757: 723: 662: 624: 583:is a complex number 243:Carl Friedrich Gauss 178:Isolated singularity 120:Holomorphic function 2375:Sendov's conjecture 2340:Gauss–Lucas theorem 2301:, and the function 2120:Function on a curve 1538:{\displaystyle |n|} 1504:is a pole of order 1368:{\displaystyle |n|} 1129:is an integer, and 944:as a pole of order 933:as a zero of order 853:{\displaystyle |n|} 830:is a zero of order 417:if for every point 130:Formal power series 92:Unit complex number 2453:Weisstein, Eric W. 2320:Argument principle 2285: 2245: 2213: 2177: 2110:rational functions 2090: 2054:around the origin. 2044: 2013: 1958: 1882: 1850: 1821: 1788: 1684: 1651: 1610: 1535: 1500:In this case, the 1484: 1455: 1408: 1365: 1335: 1244: 1155: 1112: 1069: 1004: 971:Riemann hypothesis 898: 850: 820: 788:(or multiplicity) 770: 736: 706: 637: 555:if every point of 535:, that is, if its 527:at every point of 447:is meromorphic in 208:Laplace's equation 188:Argument principle 2000: 1956: 1786: 1649: 1590:rational function 1502:point at infinity 1482: 1440: 1051: 487:point at infinity 451:, then a zero of 317: 316: 203:Harmonic function 115:Analytic function 101:Complex functions 87:Complex conjugate 16:(Redirected from 2487: 2480:Complex analysis 2466: 2465: 2440: 2424: 2405: 2370:RouchĂ©'s theorem 2350:Marden's theorem 2304: 2297:If the curve is 2294: 2292: 2291: 2286: 2262: 2258: 2254: 2252: 2251: 2246: 2222: 2220: 2219: 2214: 2212: 2211: 2186: 2184: 2183: 2178: 2166: 2162: 2158: 2154: 2099: 2097: 2096: 2091: 2053: 2051: 2050: 2045: 2043: 2042: 2022: 2020: 2019: 2014: 2012: 2001: 1998: 1967: 1965: 1964: 1959: 1957: 1955: 1948: 1947: 1937: 1926: 1891: 1889: 1888: 1883: 1859: 1857: 1856: 1851: 1830: 1828: 1827: 1822: 1797: 1795: 1794: 1789: 1787: 1785: 1784: 1783: 1762: 1761: 1739: 1728: 1693: 1691: 1690: 1685: 1660: 1658: 1657: 1652: 1650: 1642: 1584: 1566: 1562: 1551: 1544: 1542: 1541: 1536: 1534: 1526: 1514: 1507: 1493: 1491: 1490: 1485: 1483: 1481: 1480: 1471: 1457: 1454: 1429: 1417: 1415: 1414: 1409: 1374: 1372: 1371: 1366: 1364: 1356: 1344: 1342: 1341: 1336: 1334: 1333: 1332: 1324: 1314: 1313: 1295: 1294: 1293: 1285: 1268: 1261: 1257: 1253: 1251: 1250: 1245: 1243: 1242: 1241: 1233: 1220: 1219: 1201: 1200: 1199: 1191: 1171: 1164: 1162: 1161: 1156: 1148: 1147: 1128: 1121: 1119: 1118: 1113: 1108: 1107: 1098: 1097: 1079: 1078: 1068: 1018:is the sum of a 1017: 1013: 1011: 1010: 1005: 1000: 999: 980: 968: 950: 943: 939: 932: 928: 907: 905: 904: 899: 891: 883: 863: 859: 857: 856: 851: 849: 841: 829: 827: 826: 821: 819: 818: 802: 795: 791: 779: 777: 776: 771: 769: 768: 752: 745: 743: 742: 737: 735: 734: 715: 713: 712: 707: 693: 692: 683: 682: 654: 646: 644: 643: 638: 636: 635: 619: 612: 605: 597: 586: 582: 569: 562: 558: 554: 542: 530: 526: 523:with respect to 518: 507: 472: 465: 462:, and a pole of 461: 454: 450: 446: 440:is holomorphic. 439: 432: 428: 424: 420: 416: 405: 398: 377: 370: 364:of the function 359: 355: 321:complex analysis 309: 302: 295: 279: 278: 263:Karl Weierstrass 258:Bernhard Riemann 248:Jacques Hadamard 77:Imaginary number 57: 47:Complex analysis 41: 39:Complex analysis 30: 21: 2495: 2494: 2490: 2489: 2488: 2486: 2485: 2484: 2470: 2469: 2451: 2450: 2447: 2427: 2421: 2408: 2402: 2388:Conway, John B. 2386: 2383: 2316: 2302: 2265: 2264: 2260: 2256: 2225: 2224: 2200: 2189: 2188: 2169: 2168: 2164: 2160: 2156: 2152: 2138:Riemann surface 2122: 2067: 2066: 2034: 2029: 2028: 1999: for  1974: 1973: 1939: 1938: 1927: 1905: 1904: 1862: 1861: 1833: 1832: 1804: 1803: 1775: 1753: 1740: 1729: 1707: 1706: 1667: 1666: 1621: 1620: 1606:domain coloring 1598: 1582: 1564: 1560: 1555:For example, a 1546: 1517: 1516: 1509: 1505: 1472: 1458: 1435: 1434: 1427: 1385: 1384: 1381: 1347: 1346: 1315: 1305: 1276: 1271: 1270: 1263: 1259: 1255: 1221: 1211: 1179: 1174: 1173: 1166: 1136: 1131: 1130: 1126: 1099: 1089: 1070: 1031: 1030: 1015: 991: 986: 985: 974: 963: 945: 941: 934: 930: 926: 921:Because of the 874: 873: 861: 832: 831: 810: 805: 804: 797: 793: 789: 760: 755: 754: 747: 726: 721: 720: 684: 674: 660: 659: 652: 627: 622: 621: 617: 607: 603: 588: 584: 580: 564: 560: 556: 552: 540: 528: 524: 516: 505: 499: 467: 463: 456: 452: 448: 444: 434: 430: 426: 422: 418: 414: 403: 397: 391: 372: 365: 357: 354: 348: 313: 273: 183:Residue theorem 158:Local primitive 148:Zeros and poles 63:Complex numbers 33: 28: 23: 22: 18:Poles and zeros 15: 12: 11: 5: 2493: 2491: 2483: 2482: 2472: 2471: 2468: 2467: 2446: 2445:External links 2443: 2442: 2441: 2429:Henrici, Peter 2425: 2419: 2406: 2400: 2382: 2379: 2378: 2377: 2372: 2367: 2362: 2360:Pole–zero plot 2357: 2352: 2347: 2342: 2337: 2332: 2327: 2322: 2315: 2312: 2284: 2281: 2278: 2275: 2272: 2244: 2241: 2238: 2235: 2232: 2210: 2207: 2203: 2199: 2196: 2176: 2121: 2118: 2106: 2105: 2102: 2101: 2100: 2089: 2086: 2083: 2080: 2077: 2074: 2061: 2060: 2056: 2055: 2041: 2037: 2011: 2007: 2004: 1996: 1993: 1990: 1987: 1984: 1981: 1970: 1969: 1968: 1954: 1951: 1946: 1942: 1936: 1933: 1930: 1924: 1921: 1918: 1915: 1912: 1899: 1898: 1894: 1893: 1881: 1878: 1875: 1872: 1869: 1849: 1846: 1843: 1840: 1820: 1817: 1814: 1811: 1800: 1799: 1798: 1782: 1778: 1774: 1771: 1768: 1765: 1760: 1756: 1752: 1749: 1746: 1743: 1738: 1735: 1732: 1726: 1723: 1720: 1717: 1714: 1701: 1700: 1696: 1695: 1683: 1680: 1677: 1674: 1663: 1662: 1661: 1648: 1645: 1640: 1637: 1634: 1631: 1628: 1615: 1614: 1597: 1594: 1576:Riemann sphere 1533: 1529: 1525: 1495: 1494: 1479: 1475: 1470: 1467: 1464: 1461: 1453: 1450: 1447: 1443: 1407: 1404: 1401: 1398: 1395: 1392: 1380: 1377: 1363: 1359: 1355: 1331: 1327: 1323: 1318: 1312: 1308: 1304: 1301: 1298: 1292: 1288: 1284: 1279: 1240: 1236: 1232: 1228: 1224: 1218: 1214: 1210: 1207: 1204: 1198: 1194: 1190: 1186: 1182: 1154: 1151: 1146: 1143: 1139: 1123: 1122: 1111: 1106: 1102: 1096: 1092: 1088: 1085: 1082: 1077: 1073: 1067: 1064: 1061: 1058: 1054: 1050: 1047: 1044: 1041: 1038: 1024:principal part 1020:Laurent series 1003: 998: 994: 956:gamma function 897: 894: 890: 886: 882: 848: 844: 840: 817: 813: 767: 763: 733: 729: 717: 716: 705: 702: 699: 696: 691: 687: 681: 677: 673: 670: 667: 634: 630: 521:differentiable 498: 495: 491:multiplicities 395: 352: 315: 314: 312: 311: 304: 297: 289: 286: 285: 284: 283: 268: 267: 266: 265: 260: 255: 250: 245: 240: 238:Leonhard Euler 235: 227: 226: 220: 219: 213: 212: 211: 210: 205: 200: 195: 190: 185: 180: 175: 173:Laurent series 170: 168:Winding number 165: 160: 155: 150: 142: 141: 135: 134: 133: 132: 127: 122: 117: 112: 104: 103: 97: 96: 95: 94: 89: 84: 79: 74: 66: 65: 59: 58: 50: 49: 43: 42: 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 2492: 2481: 2478: 2477: 2475: 2463: 2462: 2457: 2454: 2449: 2448: 2444: 2438: 2434: 2430: 2426: 2422: 2420:0-387-94460-5 2416: 2412: 2407: 2403: 2401:0-387-90328-3 2397: 2393: 2389: 2385: 2384: 2380: 2376: 2373: 2371: 2368: 2366: 2363: 2361: 2358: 2356: 2353: 2351: 2348: 2346: 2343: 2341: 2338: 2336: 2333: 2331: 2330:Filter design 2328: 2326: 2323: 2321: 2318: 2317: 2313: 2311: 2309: 2300: 2295: 2282: 2276: 2270: 2242: 2236: 2230: 2208: 2205: 2201: 2197: 2194: 2174: 2149: 2147: 2143: 2139: 2135: 2134:complex plane 2131: 2127: 2126:complex curve 2119: 2117: 2115: 2111: 2103: 2087: 2084: 2078: 2072: 2065: 2064: 2063: 2062: 2058: 2057: 2039: 2035: 2026: 2025:Taylor series 2005: 2002: 1994: 1991: 1988: 1985: 1982: 1979: 1971: 1952: 1949: 1944: 1940: 1934: 1931: 1928: 1922: 1916: 1910: 1903: 1902: 1901: 1900: 1896: 1895: 1879: 1876: 1873: 1870: 1867: 1847: 1844: 1841: 1838: 1818: 1815: 1812: 1809: 1801: 1780: 1772: 1769: 1766: 1758: 1750: 1747: 1744: 1736: 1733: 1730: 1724: 1718: 1712: 1705: 1704: 1703: 1702: 1698: 1697: 1681: 1678: 1675: 1672: 1664: 1646: 1643: 1638: 1632: 1626: 1619: 1618: 1617: 1616: 1612: 1611: 1607: 1602: 1595: 1593: 1591: 1586: 1579: 1577: 1573: 1572:complex plane 1568: 1567:at infinity. 1558: 1553: 1549: 1527: 1512: 1503: 1498: 1477: 1473: 1465: 1459: 1445: 1433: 1432: 1431: 1425: 1421: 1402: 1396: 1390: 1378: 1376: 1357: 1325: 1310: 1306: 1302: 1299: 1286: 1277: 1266: 1234: 1226: 1216: 1212: 1208: 1205: 1192: 1184: 1180: 1169: 1152: 1149: 1144: 1141: 1137: 1109: 1104: 1094: 1090: 1086: 1083: 1075: 1071: 1065: 1062: 1059: 1056: 1052: 1048: 1042: 1036: 1029: 1028: 1027: 1025: 1021: 1001: 996: 992: 982: 978: 972: 966: 961: 957: 952: 949: 938: 924: 919: 917: 912: 910: 895: 892: 884: 871: 867: 842: 815: 811: 800: 787: 783: 765: 761: 750: 731: 727: 700: 694: 689: 679: 675: 671: 668: 658: 657: 656: 650: 649:complex plane 632: 628: 614: 611: 606:is a zero of 601: 595: 591: 578: 577: 571: 568: 550: 546: 545:neighbourhood 538: 537:Taylor series 534: 522: 515: 511: 504: 496: 494: 492: 488: 484: 483:complex plane 480: 476: 471: 466:is a zero of 460: 455:is a pole of 441: 438: 413: 409: 400: 394: 389: 388:neighbourhood 385: 381: 376: 369: 363: 351: 346: 342: 338: 334: 330: 326: 322: 310: 305: 303: 298: 296: 291: 290: 288: 287: 282: 277: 272: 271: 270: 269: 264: 261: 259: 256: 254: 251: 249: 246: 244: 241: 239: 236: 234: 231: 230: 229: 228: 225: 221: 218: 214: 209: 206: 204: 201: 199: 198:Schwarz lemma 196: 194: 193:Conformal map 191: 189: 186: 184: 181: 179: 176: 174: 171: 169: 166: 164: 161: 159: 156: 154: 151: 149: 146: 145: 144: 143: 140: 136: 131: 128: 126: 123: 121: 118: 116: 113: 111: 108: 107: 106: 105: 102: 98: 93: 90: 88: 85: 83: 82:Complex plane 80: 78: 75: 73: 70: 69: 68: 67: 64: 60: 56: 52: 51: 48: 44: 40: 36: 32: 31: 19: 2459: 2432: 2413:. Springer. 2410: 2394:. Springer. 2391: 2296: 2150: 2146:isomorphisms 2125: 2123: 2107: 2059:The function 1897:The function 1699:The function 1613:The function 1587: 1580: 1569: 1554: 1547: 1510: 1499: 1496: 1419: 1382: 1264: 1167: 1124: 1023: 983: 976: 964: 953: 947: 936: 922: 920: 913: 908: 869: 865: 798: 785: 781: 748: 718: 615: 609: 599: 593: 589: 574: 572: 566: 500: 478: 474: 469: 458: 442: 436: 401: 392: 374: 367: 349: 324: 318: 147: 139:Basic theory 38: 1430:such that 1383:A function 1379:At infinity 870:simple pole 866:Simple zero 655:such that 549:meromorphic 514:open domain 510:holomorphic 497:Definitions 408:meromorphic 402:A function 380:holomorphic 360:if it is a 329:singularity 253:Kiyoshi Oka 72:Real number 2381:References 2187:such that 2128:, that is 1559:of degree 1557:polynomial 1165:Again, if 587:such that 386:) in some 2461:MathWorld 2271:ϕ 2231:ϕ 2206:− 2202:ϕ 2198:∘ 2175:ϕ 2006:∈ 1989:π 1950:− 1932:− 1874:− 1845:− 1748:− 1452:∞ 1449:→ 1394:↦ 1303:− 1262:, and if 1227:− 1209:− 1185:− 1150:≠ 1142:− 1087:− 1063:− 1060:≥ 1053:∑ 672:− 519:if it is 485:plus the 2474:Category 2431:(1974). 2390:(1986). 2314:See also 2136:and the 1596:Examples 916:isolated 533:analytic 412:open set 2299:compact 979:) = 1/2 803:, then 753:, then 647:of the 337:complex 2456:"Pole" 2417:  2398:  2255:Then, 2142:charts 1588:Every 1550:< 0 1513:> 0 1170:> 0 1125:where 909:Degree 801:< 0 751:> 0 512:in an 410:in an 382:(i.e. 224:People 923:order 796:. If 786:order 780:is a 596:) = 0 479:poles 475:zeros 335:of a 331:of a 2415:ISBN 2396:ISBN 1570:The 1424:disk 868:and 782:pole 600:pole 598:. A 576:zero 563:and 477:and 433:and 371:and 362:zero 325:pole 2163:of 2027:of 1581:If 1545:if 1508:if 1442:lim 1418:is 1267:≀ 0 975:Re( 967:= 1 860:of 792:of 784:of 616:If 602:of 551:in 508:is 443:If 421:of 406:is 390:of 378:is 319:In 2476:: 2458:. 2435:. 2310:. 2148:. 2116:. 1578:. 1552:. 1375:. 1153:0. 981:. 896:1. 864:. 613:. 608:1/ 573:A 565:1/ 501:A 468:1/ 457:1/ 435:1/ 399:. 373:1/ 366:1/ 37:→ 2464:. 2439:. 2423:. 2404:. 2303:f 2283:. 2280:) 2277:z 2274:( 2261:n 2257:z 2243:. 2240:) 2237:z 2234:( 2209:1 2195:f 2165:M 2161:z 2157:M 2153:f 2088:z 2085:= 2082:) 2079:z 2076:( 2073:f 2040:z 2036:e 2010:Z 2003:n 1995:i 1992:n 1986:2 1983:= 1980:z 1953:1 1945:z 1941:e 1935:4 1929:z 1923:= 1920:) 1917:z 1914:( 1911:f 1880:, 1877:2 1871:= 1868:z 1848:7 1842:= 1839:z 1819:, 1816:5 1813:= 1810:z 1781:3 1777:) 1773:7 1770:+ 1767:z 1764:( 1759:2 1755:) 1751:5 1745:z 1742:( 1737:2 1734:+ 1731:z 1725:= 1722:) 1719:z 1716:( 1713:f 1682:, 1679:0 1676:= 1673:z 1647:z 1644:3 1639:= 1636:) 1633:z 1630:( 1627:f 1583:f 1565:n 1561:n 1548:n 1532:| 1528:n 1524:| 1511:n 1506:n 1478:n 1474:z 1469:) 1466:z 1463:( 1460:f 1446:z 1428:n 1406:) 1403:z 1400:( 1397:f 1391:z 1362:| 1358:n 1354:| 1330:| 1326:n 1322:| 1317:) 1311:0 1307:z 1300:z 1297:( 1291:| 1287:n 1283:| 1278:a 1265:n 1260:n 1256:n 1239:| 1235:n 1231:| 1223:) 1217:0 1213:z 1206:z 1203:( 1197:| 1193:n 1189:| 1181:a 1168:n 1145:n 1138:a 1127:n 1110:, 1105:k 1101:) 1095:0 1091:z 1084:z 1081:( 1076:k 1072:a 1066:n 1057:k 1049:= 1046:) 1043:z 1040:( 1037:f 1016:f 1002:, 997:0 993:z 977:z 965:z 948:n 946:– 942:n 937:n 935:– 931:n 927:n 893:= 889:| 885:n 881:| 862:f 847:| 843:n 839:| 816:0 812:z 799:n 794:f 790:n 766:0 762:z 749:n 732:0 728:z 704:) 701:z 698:( 695:f 690:n 686:) 680:0 676:z 669:z 666:( 653:n 633:0 629:z 618:f 610:f 604:f 594:z 592:( 590:f 585:z 581:f 567:f 561:f 557:U 553:U 541:U 529:U 525:z 517:U 506:z 470:f 464:f 459:f 453:f 449:U 445:f 437:f 431:f 427:z 423:U 419:z 415:U 404:f 396:0 393:z 375:f 368:f 358:f 353:0 350:z 308:e 301:t 294:v 20:)

Index

Poles and zeros
Mathematical analysis
Complex analysis

Complex numbers
Real number
Imaginary number
Complex plane
Complex conjugate
Unit complex number
Complex functions
Complex-valued function
Analytic function
Holomorphic function
Cauchy–Riemann equations
Formal power series
Basic theory
Zeros and poles
Cauchy's integral theorem
Local primitive
Cauchy's integral formula
Winding number
Laurent series
Isolated singularity
Residue theorem
Argument principle
Conformal map
Schwarz lemma
Harmonic function
Laplace's equation

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