User Bill Johnson

76 votes

When should a supervisor be a co-author?

answered Mar 4, 2011 at 11:22

44 votes

Accepted

Is the Invariant Subspace Problem interesting?

answered Dec 10, 2010 at 16:28

42 votes

Can $L^p(\mathbb{R})$ and $ L^q(\mathbb{R})$ be isomorphic?

answered Nov 3, 2011 at 3:45

41 votes

Probabilistic proofs of analytic facts

answered Dec 30, 2009 at 21:12

38 votes

Norms of commutators

answered Feb 7, 2012 at 16:08

37 votes

Accepted

A separable Banach space and a non-separable Banach space having the same dual space?

answered Oct 6, 2011 at 18:56

36 votes

Proofs of the uncountability of the reals

answered Nov 23, 2010 at 0:00

31 votes

How to escape the inclination to be a universalist or: How to learn to stop worrying and do some research.

answered Aug 17, 2010 at 17:49

30 votes

When is $A$ isomorphic to $A^3$?

answered Dec 30, 2009 at 21:01

30 votes

How helpful is non-standard analysis?

answered Feb 25, 2010 at 0:01

29 votes

Why do we care about $L^p$ spaces besides $p = 1$, $p = 2$, and $p = \infty$?

answered Jun 15, 2010 at 4:02

25 votes

Accepted

Can a connected planar compactum minus a point be totally disconnected?

answered Feb 27, 2010 at 20:04

23 votes

Accepted

Almost orthogonal vectors

answered May 16, 2010 at 9:35

23 votes

Quick proofs of hard theorems

answered May 16, 2010 at 19:25

23 votes

prime ideals in C([0,1])

answered Aug 16, 2010 at 21:35

22 votes

A counter example to Hahn-Banach separation theorem of convex sets.

answered Sep 3, 2010 at 18:37

21 votes

Accepted

A book you would like to write

answered Feb 3, 2011 at 20:23

21 votes

Accepted

tr(ab)=tr(ba), part 2.

answered Oct 23, 2011 at 19:24

19 votes

Example of sequences with different limits for two norms

answered Feb 1, 2011 at 11:52

19 votes

Theorems first published in textbooks?

answered Sep 17, 2010 at 11:38

18 votes

Can every uncountable subset $\mathbb{R}$ be split at some number into two parts of the same cardinality?

answered Dec 17, 2011 at 1:54

17 votes

Are there proofs that you feel you did not "understand" for a long time?

answered Jun 29, 2013 at 16:44

17 votes

Accepted

Easy proof of the fact that isotropic spaces are Euclidean

answered Oct 6, 2010 at 17:40

17 votes

Finding questions between functional analysis and set theory

answered Mar 22, 2010 at 14:35

17 votes

Accepted

Factorization of a real matrix into Hermitian x Hermitian. Is it stable ?

answered Sep 6, 2011 at 17:39

16 votes

Accepted

Containment of $c_0$

answered Jan 8, 2014 at 19:23

16 votes

Accepted

Intersection of complemented subspaces of a Banach space

answered Jan 13, 2012 at 6:12

16 votes

Accepted

Direct proof of injectivity of $L_\infty$

answered Oct 23, 2012 at 21:00

15 votes

Accepted

Quotients of $\ell_\infty$ by separable subspaces

answered Dec 10, 2013 at 19:02

15 votes

Applications of Rademacher's Theorem

answered Sep 15, 2011 at 1:08

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406 Answers

When should a supervisor be a co-author?

Is the Invariant Subspace Problem interesting?

Can $L^p(\mathbb{R})$ and $ L^q(\mathbb{R})$ be isomorphic?

Probabilistic proofs of analytic facts

Norms of commutators

A separable Banach space and a non-separable Banach space having the same dual space?

Proofs of the uncountability of the reals

How to escape the inclination to be a universalist or: How to learn to stop worrying and do some research.

When is $A$ isomorphic to $A^3$?

How helpful is non-standard analysis?

Why do we care about $L^p$ spaces besides $p = 1$, $p = 2$, and $p = \infty$?

Can a connected planar compactum minus a point be totally disconnected?

Almost orthogonal vectors

Quick proofs of hard theorems

prime ideals in C([0,1])

A counter example to Hahn-Banach separation theorem of convex sets.

A book you would like to write

tr(ab)=tr(ba), part 2.

Example of sequences with different limits for two norms

Theorems first published in textbooks?

Can every uncountable subset $\mathbb{R}$ be split at some number into two parts of the same cardinality?

Are there proofs that you feel you did not "understand" for a long time?

Easy proof of the fact that isotropic spaces are Euclidean

Finding questions between functional analysis and set theory

Factorization of a real matrix into Hermitian x Hermitian. Is it stable ?

Containment of $c_0$

Intersection of complemented subspaces of a Banach space

Direct proof of injectivity of $L_\infty$

Quotients of $\ell_\infty$ by separable subspaces

Applications of Rademacher's Theorem