Knowledge

Talk:Center (algebra)

Source 📝

84: 74: 53: 22: 165:
This gives the impression that every ring R is an algebra over every commutative subring, which is false, take for example the quaternions as a ring and the complex numbers as a commutative subring. Maybe one should omit the word "so" and everything's fine? --
228:, is taken to the coproduct of commutative rings (the tensor product over ℤ). Does anyone know any more about this? I'd sure appreciate some references for further reading on the category of rings and commutative rings. Much thanks. -- 223:
is continuous, preserving products, pullbacks, the terminal object, and other limits, and I'd thought maybe the center of rings functor preserved colimits, but I'm not 100% sure that the coproduct of rings, the
140: 320: 130: 315: 106: 97: 58: 212:. I think that merits each of those having their own page, or at least vastly expanded sections rather than disambiguation. 258:(the Hamiltonian quaternions) is a ring homomorphism out of a commutative ring whose image is not central, which means that 250:, for example, is a group homomorphism that does not restrict to a homomorphism between centers. Also, the inclusion of 33: 282:. The inclusion functors do not preserve colimits, so they cannot have right adjoints. The left adjoints are given by 162:
I don't think that one should write "The center is a commutative subring of R, so R is an algebra over its center."
286:
and an analogous quotient for rings (quotient out by the 2-sided ideal generated by all ring-theoretic commutators
181: 39: 83: 167: 177: 105:
on Knowledge. If you would like to participate, please visit the project page, where you can join
296: 243:
The center is not functorial, neither for groups nor for rings. The inclusion of {e, (1 2)} into
233: 89: 73: 52: 283: 309: 229: 225: 215:
I don't know if in either case it is a left or right adjoint. I know the inclusion
102: 79: 300: 237: 185: 170: 196:
In the cases of groups and rings, the center defines a functor
15: 101:, a collaborative effort to improve the coverage of 176:I've changed "so" to "and". Thanks for noticing.-- 8: 47: 21: 19: 49: 7: 95:This article is within the scope of 38:It is of interest to the following 14: 321:Mid-priority mathematics articles 115:Knowledge:WikiProject Mathematics 118:Template:WikiProject Mathematics 82: 72: 51: 20: 316:List-Class mathematics articles 135:This article has been rated as 1: 109:and see a list of open tasks. 238:21:45, 27 August 2014 (UTC) 337: 171:10:51, 7 August 2007 (UTC) 301:17:54, 21 July 2017 (UTC) 186:23:54, 3 March 2010 (UTC) 134: 67: 46: 141:project's priority scale 98:WikiProject Mathematics 28:This article is rated 266:-algebra, but is an 121:mathematics articles 90:Mathematics portal 34:content assessment 294:), respectively. 270:-algebra because 155: 154: 151: 150: 147: 146: 328: 123: 122: 119: 116: 113: 92: 87: 86: 76: 69: 68: 63: 55: 48: 31: 25: 24: 23: 16: 336: 335: 331: 330: 329: 327: 326: 325: 306: 305: 249: 194: 160: 120: 117: 114: 111: 110: 88: 81: 61: 32:on Knowledge's 29: 12: 11: 5: 334: 332: 324: 323: 318: 308: 307: 304: 303: 284:abelianization 247: 193: 190: 189: 188: 178:Roentgenium111 159: 156: 153: 152: 149: 148: 145: 144: 133: 127: 126: 124: 107:the discussion 94: 93: 77: 65: 64: 56: 44: 43: 37: 26: 13: 10: 9: 6: 4: 3: 2: 333: 322: 319: 317: 314: 313: 311: 302: 299: 298: 297:GeoffreyT2000 293: 289: 285: 281: 277: 273: 269: 265: 261: 257: 253: 246: 242: 241: 240: 239: 235: 231: 227: 222: 218: 213: 211: 207: 203: 199: 192:Functoriality 191: 187: 183: 179: 175: 174: 173: 172: 169: 163: 157: 142: 138: 132: 129: 128: 125: 108: 104: 100: 99: 91: 85: 80: 78: 75: 71: 70: 66: 60: 57: 54: 50: 45: 41: 35: 27: 18: 17: 295: 291: 287: 279: 275: 271: 267: 263: 259: 255: 251: 244: 226:free product 220: 216: 214: 209: 205: 201: 197: 195: 164: 161: 137:Mid-priority 136: 96: 62:Mid‑priority 40:WikiProjects 168:130.83.2.27 112:Mathematics 103:mathematics 59:Mathematics 310:Categories 30:List-class 262:is not a 230:Daviddwd 158:Subring 139:on the 36:scale. 254:into 217:CRing 210:CRing 278:) = 234:talk 221:Ring 206:Ring 204:and 182:talk 198:Grp 131:Mid 312:: 292:yx 290:− 288:xy 236:) 219:→ 208:→ 202:Ab 200:→ 184:) 280:R 276:H 274:( 272:Z 268:R 264:C 260:H 256:H 252:C 248:3 245:S 232:( 180:( 143:. 42::

Index

content assessment
WikiProjects
WikiProject icon
Mathematics
WikiProject icon
icon
Mathematics portal
WikiProject Mathematics
mathematics
the discussion
Mid
project's priority scale
130.83.2.27
10:51, 7 August 2007 (UTC)
Roentgenium111
talk
23:54, 3 March 2010 (UTC)
free product
Daviddwd
talk
21:45, 27 August 2014 (UTC)
abelianization
GeoffreyT2000
17:54, 21 July 2017 (UTC)
Categories
List-Class mathematics articles
Mid-priority mathematics articles

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.