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Igor Rivin

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Name	Igor Rivin
Member for	2 years
Seen	Feb 21 at 15:58
Website	math.temple.edu/~rivin
Location	USA
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Professor of Mathematics at Temple University.

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57

45

votes

22

answers

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What’s the “best” proof of quadratic reciprocity?

nt.number-theory quadratic-reciprocity

apr 20 at 22:10 ACL 4,285●12●24

20

43

votes

7

answers

3k

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Is `$\sum\limits_{n=0}^\infty x^n / \sqrt{n!}$` positive?

sequences-and-series ca.analysis-and-odes

jan 11 12 at 17:21 Gottfried Helms 1,371●1●3●10

8

34

votes

2

answers

2k

views

Alternating sum of square roots of binomial coefficients

sequences-and-series ca.analysis-and-odes binomial-coefficients

mar 11 12 at 18:59 Mark Wildon 2,045●1●9●15

59

28

votes

19

answers

5k

views

Open source mathematical software.

soft-question computer-algebra big-list

sep 21 at 9:07 Xingdong Zuo 29●5

36

26

votes

9

answers

3k

views

Non-computational software useful to mathematicians

soft-question big-list mathematical-software mathematical-software

jun 7 at 14:17 darij grinberg 12.8k●1●24●75

13

24

votes

1

answer

1k

views

Do all exact 1 -> A -> AxB -> B -> 1 split for finite groups?

homological-algebra short-exact-sequences finite-groups gr.group-theory

mar 31 12 at 19:35 Dan Glasscock 355●1●7

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21

votes

12

answers

3k

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Explicit computations using the Haar measure

haar-measure reference-request examples

jul 12 at 17:14 Kjetil B Halvorsen 916●5●8

24

20

votes

11

answers

5k

views

Elementary / Interesting proofs of the Nullstellensatz

ac.commutative-algebra

jul 19 at 15:56 Matt 1●2

11

16

votes

5

answers

2k

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Pythagorean 5-tuples

nt.number-theory ac.commutative-algebra clifford-algebras lie-algebras diophantine-equations

may 13 11 at 22:06 Geoff Robinson 10.4k●1●22●29

2

16

votes

4

answers

1k

views

Is strong approximation difficult?

nt.number-theory algebraic-groups

nov 23 11 at 21:13 paul garrett 6,794●17●26

4

15

votes

2

answers

1k

views

Distinguishing congruence subgroups of the modular group

nt.number-theory modular-forms modular-group

aug 26 10 at 16:37 David Corwin 6,730●23●57

10

14

votes

6

answers

3k

views

Applications of Hardy’s inequality

ca.analysis-and-odes harmonic-analysis inequalities

jan 8 11 at 14:40 suVRit 10.3k●1●16●45

13

14

votes

11

answers

2k

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Importance of Poincaré recurrence theorem? Any example?

ds.dynamical-systems ergodic-theory

mar 23 12 at 16:36 Juan Valdez 603●2●7

13

13

votes

6

answers

1k

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Characterization of the transfer map in group theory

ct.category-theory gr.group-theory group-cohomology

dec 21 11 at 8:23 Martin Brandenburg 29.5k●2●47●133

6

12

votes

2

answers

508

views

Are surface bundles over a surface with non-zero signature necessarily complex (or algebraic)?

complex-geometry ag.algebraic-geometry gt.geometric-topology dg.differential-geometry

apr 4 at 13:38 JL 1