Znn3bq.jpeg
²é¿´: 1269  |  »Ø¸´: 6
µ±Ç°Ö»ÏÔʾÂú×ãÖ¸¶¨Ìõ¼þµÄ»ØÌû£¬µã»÷ÕâÀï²é¿´±¾»°ÌâµÄËùÓлØÌû

du0927

Ìú³æ (СÓÐÃûÆø)

[ÇóÖú] ½»´íȺA_nµÄ¸²¸ÇȺ2.A_nÖеĸöÊýÊǶàÉÙ£¿

ÇëÎÊ£¬ÓÐÈËÖªµÀ½»´íȺA_nµÄ¸²¸ÇȺ2.A_nÖеĸöÊýÊǶàÉÙÂð£¿

·¢×ÔСľ³æIOS¿Í»§¶Ë
»Ø¸´´ËÂ¥

» ²ÂÄãϲ»¶

» ±¾Ö÷ÌâÏà¹Ø¼ÛÖµÌùÍÆ¼ö£¬¶ÔÄúͬÑùÓаïÖú:

ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

du0927

Ìú³æ (СÓÐÃûÆø)

Ëͺ컨һ¶ä
ÒýÓûØÌû:
2Â¥: Originally posted by hank612 at 2015-11-27 04:34:57
ËäÈ»ÎÒ²»¶®£¬µ«ÍøÉÏÐÅÏ¢ºÜÈ«°¢
http://mathoverflow.net/questions/9406/presentation-for-the-double-cover-of-a-n

https://en.wikipedia.org/wiki/Covering_groups_of_the_alternating_and_symmetric_groups
...

1

·¢×ÔСľ³æIOS¿Í»§¶Ë
6Â¥2015-11-27 17:18:06
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû
²é¿´È«²¿ 7 ¸ö»Ø´ð

hank612

ÖÁ×ðľ³æ (ÖøÃûдÊÖ)

¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï ¡ï
du0927(Edstrayer´ú·¢): ½ð±Ò+20 2015-12-23 01:09:50
ËäÈ»ÎÒ²»¶®£¬µ«ÍøÉÏÐÅÏ¢ºÜÈ«°¢
http://mathoverflow.net/question ... double-cover-of-a-n

https://en.wikipedia.org/wiki/Co ... nd_symmetric_groups

¡°the alternating group of degree n has one isomorphism class of Schur cover, which has order n! except when n is 6 or 7, in which case the Schur cover has order 3⋅n!.¡±

» ±¾ÌûÒÑ»ñµÃµÄºì»¨£¨×îÐÂ10¶ä£©

We_must_know. We_will_know.
2Â¥2015-11-27 04:34:57
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

du0927

Ìú³æ (СÓÐÃûÆø)

Ëͺ컨һ¶ä
ÒýÓûØÌû:
2Â¥: Originally posted by hank612 at 2015-11-27 04:34:57
ËäÈ»ÎÒ²»¶®£¬µ«ÍøÉÏÐÅÏ¢ºÜÈ«°¢
http://mathoverflow.net/questions/9406/presentation-for-the-double-cover-of-a-n

https://en.wikipedia.org/wiki/Covering_groups_of_the_alternating_and_symmetric_groups
...

Ê®·Ö¸Ðл°¡

·¢×ÔСľ³æIOS¿Í»§¶Ë
4Â¥2015-11-27 16:07:39
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

du0927

Ìú³æ (СÓÐÃûÆø)

Ëͺ컨һ¶ä
ÒýÓûØÌû:
2Â¥: Originally posted by hank612 at 2015-11-27 04:34:57
ËäÈ»ÎÒ²»¶®£¬µ«ÍøÉÏÐÅÏ¢ºÜÈ«°¢
http://mathoverflow.net/questions/9406/presentation-for-the-double-cover-of-a-n

https://en.wikipedia.org/wiki/Covering_groups_of_the_alternating_and_symmetric_groups
...

²»»á·¢½ð±Ò^_^

·¢×ÔСľ³æIOS¿Í»§¶Ë
5Â¥2015-11-27 17:17:43
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû
×î¾ßÈËÆøÈÈÌûÍÆ¼ö [²é¿´È«²¿] ×÷Õß »Ø/¿´ ×îºó·¢±í
[¿¼ÑÐ] 279ѧ˶ʳƷרҵÇóµ÷¼ÁԺУ 20+4 ¹Â¶ÀµÄÀǰ®³ÔÑò 2026-04-12 18/900 2026-04-13 01:17 by ÐÒÃâ ..
[¿¼ÑÐ] ²ÄÁϹ¤³Ì281»¹Óе÷¼Á»ú»áÂð +29 xaw. 2026-04-11 30/1500 2026-04-13 00:20 by 1005715100
[¿¼ÑÐ] 0831Ò»ÂÖµ÷¼Áʧ°ÜÇóÖú +10 СÐÜî£î£_s 2026-04-11 10/500 2026-04-12 22:43 by ³¤¹­°Á
[¿¼ÑÐ] 272·Ö²ÄÁÏ×ÓÇóµ÷¼Á +40 Loy0361 2026-04-10 52/2600 2026-04-12 19:23 by laoshidan
[¿¼ÑÐ] 0856ר˶Çóµ÷¼Á Ï£ÍûÊÇaÇøÔºÐ£ +22 ºÃºÃÐÝÏ¢ºÃ²»ºÃ 2026-04-09 25/1250 2026-04-12 17:09 by ajpv·çÀ×
[¿¼ÑÐ] µ÷¼Á +25 ²»·ê´º 2026-04-07 26/1300 2026-04-12 11:53 by ´óÁ¦Ë®ÊÖÁ¦´óÎÞÇ
[¿¼ÑÐ] 277 ÊýÒ»104£¬Ñ§Ë¶£¬Çóµ÷¼Á +21 Æ¿×ÓPZ 2026-04-09 23/1150 2026-04-11 23:12 by labixiaoqiao
[¿¼ÑÐ] Çóµ÷¼Á +11 ôæôæÒ»ÊéÉú 2026-04-09 11/550 2026-04-11 19:57 by ÄæË®³Ë·ç
[¿¼ÑÐ] 283Çóµ÷¼Á 086004¿¼Ó¢¶þÊý¶þ +17 ÄǸöàà×Ó 2026-04-10 18/900 2026-04-11 16:27 by Ã÷Ô´ËʱÓÐ
[¿¼ÑÐ] Çóµ÷¼Á +3 θ¾·ÂÎÀÛÁË 2026-04-11 5/250 2026-04-11 14:13 by luhong1990
[¿¼ÑÐ] 346£¬¹¤¿Æ0854Çóµ÷¼Á£¬×¨Ë¶ +7 moser233 2026-04-10 8/400 2026-04-11 08:52 by Öí»á·É
[¿¼ÑÐ] 083200 305·Ö Çó¶þÂÖµ÷¼Á ²»½ÓÊÜ¿çרҵ +9 Claireyyyy 2026-04-09 10/500 2026-04-10 21:21 by Claireyyyy
[¿¼ÑÐ] 085800 ÄÜÔ´¶¯Á¦Çóµ÷¼Á +6 °¢biu°¡°¡°¡°¡°¡ 2026-04-10 6/300 2026-04-10 15:03 by hemengdong
[¿¼ÑÐ] Ò»Ö¾Ô¸ÖÐÄÏ´óѧÎïÀíѧ£¬Ó¢Ò»66£¬Çóµ÷¼Á +4 ³¤ÑÌì½ì» 2026-04-08 5/250 2026-04-10 10:31 by Ó±¹û¶ù
[¿¼ÑÐ] ÉúÎïѧÇóµ÷¼Á Ò»Ö¾Ô¸»¦9£¬326·Ö +7 Áõīī 2026-04-06 7/350 2026-04-10 08:11 by kangsm
[¿¼ÑÐ] ¸´ÊÔµ÷¼Á£¬Ò»Ö¾Ô¸Ö£ÖÝ´óѧ²ÄÁÏÓ뻯¹¤289·Ö +31 ˶ÐǸ° 2026-04-08 31/1550 2026-04-09 16:54 by Delta2012
[¿¼ÑÐ] 334Çóµ÷¼Á +16 Riot2025 2026-04-08 17/850 2026-04-09 09:28 by wdyheheeh
[¿¼ÑÐ] Çó¿¼ÑвÄÁϵ÷¼Á +3 ²Ä»¯Àî¿É 2026-04-07 3/150 2026-04-08 00:21 by JourneyLucky
[¿¼ÑÐ] ¼ÆËã»ú11408 287 Çóµ÷¼Á +3 LiLe5 2026-04-07 3/150 2026-04-07 23:15 by shanqishi
[¿¼ÑÐ] 362Çóµ÷¼ÁÒ»Ö¾Ô¸ÖйúʯÓÍ´óѧ +4 ÎÒÒª¿¼´ó 2026-04-06 6/300 2026-04-06 14:11 by Î޼ʵIJÝÔ­
ÐÅÏ¢Ìáʾ
ÇëÌî´¦ÀíÒâ¼û