User Keivan Karai

33 votes

Jokes in the sense of Littlewood: examples?

answered Sep 16, 2010 at 12:04

28 votes

Wonderful applications of the Vandermonde determinant

linear-algebra big-list examples determinants

answered Oct 25, 2010 at 17:27

27 votes

Accepted

prime ideals in C([0,1])

fa.functional-analysis ra.rings-and-algebras

answered Aug 17, 2010 at 3:42

26 votes

Why are free groups residually finite?

gr.group-theory topological-groups profinite-groups

answered Apr 6, 2010 at 10:24

25 votes

Accepted

Ultraproducts of finite cyclic groups

ultrapowers gr.group-theory

answered Aug 31, 2010 at 10:47

23 votes

Accepted

Zariski-closed subsemigroups of SL_n(C) are groups

reference-request linear-algebra algebraic-groups

answered Nov 22, 2010 at 12:50

16 votes

A question about "Zariski dense" arguments

ag.algebraic-geometry gn.general-topology

answered Aug 23, 2014 at 15:18

14 votes

German mathematical terms like "Nullstellensatz"

terminology big-list

answered Apr 19, 2011 at 17:57

13 votes

Partition of R into midpoint convex sets

real-analysis set-theory measure-theory

answered Apr 23, 2010 at 12:41

10 votes

What is your favorite "strange" function?

big-list gm.general-mathematics

answered Apr 23, 2010 at 12:32

10 votes

Any factor group of a finite abelian group is isomorphic to some subgroup

gr.group-theory abelian-groups

answered Aug 8, 2010 at 1:15

10 votes

Accepted

discrete subgroups in p-adic Lie groups?

arithmetic-groups

answered Oct 18, 2010 at 10:33

10 votes

A set for which it is hard to determine whether or not it is countable.

gm.general-mathematics

answered Mar 22, 2011 at 13:40

9 votes

Accepted

Amenable exponential growth

gr.group-theory measure-theory ca.classical-analysis-and-odes

answered Feb 20, 2011 at 19:17

9 votes

Uniform lattices in semisimple Lie groups

dg.differential-geometry gr.group-theory lie-groups

answered Aug 23, 2011 at 2:58

7 votes

Automorphisms of $SL_n(\mathbb{Z})$

gr.group-theory

answered Mar 3, 2011 at 11:23

6 votes

Function with range equal to whole reals on every open set

ca.classical-analysis-and-odes real-analysis

answered Jul 16, 2010 at 12:22

6 votes

Origins of Mathematical Symbols/Names

soft-question notation

answered Apr 15, 2010 at 8:53

4 votes

Dense cyclic subgroup

topological-groups

answered Aug 31, 2010 at 10:29

4 votes

Accepted

description of functions of conditionally negative type on a group

examples reference-request fa.functional-analysis gr.group-theory

answered Sep 2, 2010 at 9:54

4 votes

When does the set of isometries form a group?

geometry mg.metric-geometry

answered Sep 17, 2011 at 16:35

3 votes

Undergraduate Probability Topics

teaching big-list

answered Sep 2, 2010 at 9:41

3 votes

Random Walk anecdote.

ho.history-overview

answered Apr 21, 2010 at 9:43

3 votes

Are extensions of linear groups linear?

gr.group-theory

answered Apr 28, 2010 at 8:49

2 votes

How Can I Tell when A Subgroup of a Lie Group is Generated by Unipotents?

gr.group-theory rt.representation-theory lie-groups ergodic-theory

answered Apr 26, 2010 at 7:38

2 votes

Uniqueness in Composition of Polynomials

ds.dynamical-systems co.combinatorics

answered Mar 25, 2010 at 14:06

2 votes

Importance of Poincaré recurrence theorem? Any example?

ds.dynamical-systems ergodic-theory

answered Sep 17, 2011 at 3:59

2 votes

A large deviation / binomial coefficients bound

co.combinatorics probability-distributions reference-request

answered Apr 21, 2011 at 10:02

2 votes

arithmetic groups VS. Zariski dense discrete subgroups?

arithmetic-groups

answered Nov 17, 2010 at 15:11

2 votes

Problems where we can't make a canonical choice, solved by looking at all choices at once

soft-question big-list

answered Dec 21, 2010 at 11:23

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38 Answers

Jokes in the sense of Littlewood: examples?

Wonderful applications of the Vandermonde determinant

prime ideals in C([0,1])

Why are free groups residually finite?

Ultraproducts of finite cyclic groups

Zariski-closed subsemigroups of SL_n(C) are groups

A question about "Zariski dense" arguments

German mathematical terms like "Nullstellensatz"

Partition of R into midpoint convex sets

What is your favorite "strange" function?

Any factor group of a finite abelian group is isomorphic to some subgroup

discrete subgroups in p-adic Lie groups?

A set for which it is hard to determine whether or not it is countable.

Amenable exponential growth

Uniform lattices in semisimple Lie groups

Automorphisms of $SL_n(\mathbb{Z})$

Function with range equal to whole reals on every open set

Origins of Mathematical Symbols/Names

Dense cyclic subgroup

description of functions of conditionally negative type on a group

When does the set of isometries form a group?

Undergraduate Probability Topics

Random Walk anecdote.

Are extensions of linear groups linear?

How Can I Tell when A Subgroup of a Lie Group is Generated by Unipotents?

Uniqueness in Composition of Polynomials

Importance of Poincaré recurrence theorem? Any example?

A large deviation / binomial coefficients bound

arithmetic groups VS. Zariski dense discrete subgroups?

Problems where we can't make a canonical choice, solved by looking at all choices at once