Theo Johnson-Freyd's user avatar
Theo Johnson-Freyd's user avatar
Theo Johnson-Freyd's user avatar
Theo Johnson-Freyd
  • Member for 10 years, 9 months
  • Last seen more than a week ago
21 votes
Accepted

Prove that $f$ is a constant function

12 votes

Relation of Hodge Theorem to Eigenfunction Basis of Laplacian

12 votes
Accepted

Factoring $a^2+b^2+c^2$?

12 votes
Accepted

Prove that $e^{\sum 1/p_k^2} > \pi/2$

12 votes

How should I show that the Lie algebra so(6) of SO(6) is isomorphic to the Lie algebra su(4) of SU(4)?

12 votes
Accepted

Remainder when $123456789101112\ldots$ is divided by $75$

9 votes
Accepted

Lie derivative along time-dependent vector fields

8 votes
Accepted

Trace of Integral

8 votes

How to describe all normal subgroups of the dihedral group Dn?

8 votes
Accepted

Probability that 3 number chosen from set is greater than other 3 numbers

7 votes

Prove that $a < b\sqrt{3}$ under conditions given

6 votes

a property of skew-symmetric matrix (arising from game theory)

6 votes
Accepted

Order of automorphism group

6 votes

How prove this $\tan{\frac{2\pi}{13}}+4\sin{\frac{6\pi}{13}}=\sqrt{13+2\sqrt{13}}$

6 votes
Accepted

Question regarding isomorphisms in low rank Lie algebras

5 votes
Accepted

Getting rid of the square roots in the expression $\sqrt{a} + \sqrt{b} + \sqrt{c} = d$

5 votes
Accepted

Representation theory and characters

5 votes
Accepted

A derivative of an integral. Homework doubt

5 votes
Accepted

$f(x)=x^{x}$ what happens when $x$ is a negative irrational number?

5 votes
Accepted

Why cannot $1+\frac{1}{1+\frac{1}{1+\frac{1}{1+\dots}}}$ be equal to $\frac{1-\sqrt{5}}{2}$?

5 votes
Accepted

Has anyone defined a limit of a sequence of fields? In particular, what is the limit of finite fields?

4 votes
Accepted

Using a Morse function to find the number of points of each index

4 votes
Accepted

Simplifying this logarithm series

4 votes

How can I find the quotient of the LCMs of the first 116 and first 113 positive integers?

4 votes

Representing $\mathbb{R}/\mathbb{Z}$ as a matrix group.

4 votes

Product of two subgroups the whole group?

4 votes
Accepted

Solutions to $Ax=x$, where $x=(1,1,1,......1)$, for $A\in GL(n,\mathbb{C})$

3 votes
Accepted

When to begin a new paragraph?

3 votes

IMO Hong Kong TST 2014

3 votes
Accepted

Product of rotation and translation is a rotation