User Igor Rivin - MathOverflow

Igor Rivin

Member for 13 years, 4 months
Last seen more than a month ago

math.temple.edu/~rivin
USA

1,864 Answers

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2 votes

Example of a non-arithmetic Veech surface (other than regular polygon)?

answered Nov 12, 2017 at 4:36

2 votes

Accepted

Elementary question about linear algebra on a circle

answered Nov 3, 2017 at 4:42

2 votes

Accepted

Software for computing equivariants

answered Mar 21, 2018 at 20:33

2 votes

Evaluating the sum of $kl^2$ over $p,q,k,l$ such that $pk +ql = n$

answered Feb 21, 2018 at 0:53

2 votes

Choose some natural number and take $k$-th power of its digits and add that. Repeat that. How many cycles will be there?

answered Mar 30, 2018 at 13:40

2 votes

Seeking references for finding primes infinitely often

answered Dec 25, 2017 at 22:28

2 votes

positive sum of sines

answered Dec 27, 2017 at 20:38

2 votes

Lefschetz fixed-point theorem for the Frobenius map

answered Jan 2, 2018 at 3:47

2 votes

Are irreducible subgroups Zariski-dense?

answered Dec 4, 2017 at 20:08

2 votes

Accepted

Find the fixed geodesic of an orientation-preserving isometry of the $3D$ hyperboloid model

answered Dec 7, 2017 at 18:59

2 votes

On the spectrum of Hermitian matrices

answered Jan 14, 2018 at 17:47

2 votes

Accepted

Distribution of eigenvectors and eigenvalues for random, symmetric matrix

answered Jan 22, 2018 at 5:46

2 votes

Non-linear first order ODE $ \frac{\mathrm{d}y}{\mathrm{d}x} = \frac{Axy \ + \ By^2 \ + \ Cy}{Dxy \ + Ey \ +\ Fx \ + G}$

answered Jan 9, 2018 at 5:12

2 votes

Smallest tile to isohedrally tessellate the hyperbolic plane

answered Jan 29, 2018 at 0:17

2 votes

Accepted

Curious about an old algorithm which calculates modular inverse

answered Dec 10, 2016 at 19:57

2 votes

Accepted

Exact first order perturbation expansion of matrix determinant

answered Jan 22, 2017 at 3:08

2 votes

Zariski density of conjugates of $SL_2(\mathbb{Z})$ in $Sp_{2g}$

answered Jan 31, 2017 at 4:01

2 votes

Accepted

All the solutions of linear Diophantine equation

answered Mar 17, 2017 at 21:29

2 votes

Cohomology of a maping torus

answered Nov 6, 2016 at 16:59

2 votes

An inequality regarding a recursive relation

answered Oct 5, 2016 at 13:26

2 votes

Complex varieties with non-torsion homotopy groups

answered Apr 8, 2017 at 1:22

2 votes

Accepted

Is the square root of a matrix unique?

answered Apr 3, 2017 at 20:21

2 votes

Accepted

Decomposition of integral non-generate matrices

answered Apr 11, 2017 at 0:11

2 votes

Orbits of some special actions on solution set of a arithmetic equation

answered Apr 15, 2017 at 3:01

2 votes

Algorithm for a linear optimization problem

answered May 11, 2017 at 1:12

2 votes

How to prove that index of second smallest index subgroup in $A_n$ is $n \choose 2$?

answered Jul 2, 2017 at 16:48

2 votes

Number of non-equivalent graph embeddings

answered Aug 6, 2017 at 17:34

2 votes

Maximum order of MCG finite order elements

answered Jul 5, 2017 at 21:08

2 votes

Voronoi and Delaunay

answered Jun 18, 2017 at 18:34

2 votes

Finiteness properties of mapping class groups

answered May 25, 2017 at 22:34

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