Stack Exchange

David E Speyer

Ann Arbor, MI

http://www.math.lsa.umich.edu/~speyer

Professor of Mathematics at the University of Michigan. My research interests are in combinatorial algebraic geometry, particularly Schubert calculus, matroids and cluster algebras. I also enjoy thinking about number theory and computational mathematics. Disclaimer: I will often ignore messages about old Stack Exchange posts when I am working on other things.

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Top Questions

How did Cole factor $2^{67}-1$ in 1903?

nt.number-theory ho.history-overview prime-numbers factorization asked May 22, 2015 at 15:33

mathoverflow.net

What is Lagrange Inversion good for?

mathematics-education co.combinatorics generating-functions asked Jul 16, 2010 at 1:25

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Is there a "Basic Number Theory" for elliptic curves?

nt.number-theory elliptic-curves zeta-functions birch-swinnerton-dyer asked Jul 31, 2011 at 15:15

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Can squares of infinite area always cover a unit square?

real-analysis geometry tiling asked Dec 20, 2017 at 22:41

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Why does $d^n \exp(-x-x^{-1})/(dx)^n$ only have $n$ positive real zeroes?

ca.analysis-and-odes real-analysis polynomials asked Aug 19, 2015 at 15:45

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Using Discord to support online teaching

mathematics online-learning asked Mar 13, 2020 at 16:20

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How to compute rational or integer points on elliptic curves

reference-request diophantine-equations math-software elliptic-curves faq asked Sep 27, 2012 at 14:42

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Uninsulting way to say "this will eventually be easy"

proofs language-use asked Mar 28, 2015 at 16:30

matheducators.stackexchange.com

Is it consistent with ZF that $V \to V^{\ast \ast}$ is always an isomorphism?

fa.functional-analysis linear-algebra set-theory teaching asked Jan 11, 2018 at 14:29

mathoverflow.net

What is the right version of "partitions of unity implies vanishing sheaf cohomology"

sheaf-theory cohomology ag.algebraic-geometry partition-of-unity locally-ringed-spaces asked Jan 12, 2010 at 17:48

mathoverflow.net

Top Answers

Evaluate $\int_0^1 \frac{\log \left( 1+x^{2+\sqrt{3}}\right)}{1+x}\mathrm dx$

math.stackexchange.com

How to find the Galois group of a polynomial?

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Most memorable titles

mathoverflow.net

Why do primes dislike dividing the sum of all the preceding primes?

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Invertible matrices of natural numbers are permutations... why?

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Convergence of $\sqrt{n}x_{n}$ where $x_{n+1} = \sin(x_{n})$

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Irreducibility of polynomials in two variables

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Advantages of Mathematics competition/olympiad students in Mathematical Research

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Different ways to prove $\sum_{k=1}^\infty \frac{1}{k^2}=\frac{\pi^2}{6}$ (the Basel problem)

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$\prod_{n=1}^{\infty} n^{\mu(n)}=\frac{1}{4 \pi ^2}$

mathoverflow.net

Why could Mertens not prove the prime number theorem?

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What are the most common pitfalls awaiting new users?

mathematica.stackexchange.com

Applications of the Chinese remainder theorem

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Conceptual reason why the sign of a permutation is well-defined?

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Is it morally right and pedagogically right to google answers to homework?

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Open problems with monetary rewards

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Generating a finite group from elements in each conjugacy class

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When is the product of two ideals equal to their intersection?

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Ideas for introducing Galois theory to advanced high school students

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When can one continuously prescribe a unit vector orthogonal to a given orthonormal system?

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Strengthening the induction hypothesis

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Evaluating the integral $\int_0^\infty \frac{\sin x} x \,\mathrm dx = \frac \pi 2$?

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Convergence of $\sum \limits_{n=1}^{\infty}\sin(n^k)/n$

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Computing $\prod_p(\frac{p^2-1}{p^2+1})$ without the zeta function?

mathoverflow.net

Applications of the Chinese remainder theorem

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Eigenvalues of matrix sums

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English reference for a result of Kronecker?

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How do people come up with difficult math Olympiad questions?

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What is the Hirzebruch-Riemann-Roch formula for the flag variety of a Lie algebra?

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What should be learned in a first serious schemes course?

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