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Sam Hopkins

Cambridge, MA

http://mit.edu/~shopkins

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Top Questions
86 votes

Why do combinatorial abstractions of geometric objects behave so well?

ag.algebraic-geometry co.combinatorics rt.representation-theory coxeter-groups matroid-theory asked Nov 27 '16 at 18:55
mathoverflow.net

20 votes

Which fields have multiplicative group isomorphic to additive group times Z/2Z?

fields asked Nov 15 '13 at 6:09
mathoverflow.net

19 votes

Counting problems where unlabeled is easier than labeled

co.combinatorics enumerative-combinatorics hyperplane-arrangements asked Mar 6 '16 at 22:04
mathoverflow.net

17 votes

Is there a n/2 version of the Erdős-Hanani conjecture?

co.combinatorics asked Feb 16 '13 at 1:02
mathoverflow.net

16 votes

What happened to “Research in the Mathematical Sciences”?

soft-question journals asked Aug 23 '18 at 21:38
mathoverflow.net

16 votes

Is it possible that the GHKK canonical basis for cluster algebras is the Lusztig/Kashiwara dual canonical basis?

co.combinatorics rt.representation-theory grassmannians cluster-algebras canonical-bases asked Jul 5 at 9:11
mathoverflow.net

15 votes

Is there a natural notion of completion of a Coxeter system?

gr.group-theory rt.representation-theory coxeter-groups asked Mar 5 '14 at 3:24
mathoverflow.net

13 votes

Cycle generating function of permutations with only odd cycles

co.combinatorics permutations symmetric-groups asked Aug 13 '18 at 15:32
mathoverflow.net

13 votes

Minuscule weights of parabolic sub-root systems are not far from dominant

co.combinatorics rt.representation-theory convex-polytopes root-systems asked Mar 2 '18 at 23:06
mathoverflow.net

13 votes

Significance of half-sum of positive roots belonging to root lattice?

co.combinatorics rt.representation-theory lie-algebras root-systems asked Nov 30 '16 at 17:58
mathoverflow.net

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Top Answers
44
Noteworthy, but not so famous conjectures resolved recent years
mathoverflow.net

39
Important formulas in Combinatorics
mathoverflow.net

31
New grand projects in contemporary math
mathoverflow.net

31
Examples of unexpected mathematical images
mathoverflow.net

25
“Strange” proofs of existence theorems
mathoverflow.net

24
Which popular games have been studied mathematically?
mathoverflow.net

22
Open questions about posets
mathoverflow.net

20
trace and involution permutations: Part I
mathoverflow.net

20
Theorems that impeded progress
mathoverflow.net

17
Elementary applications of linear algebra over finite fields
mathoverflow.net

16
Open questions about posets
mathoverflow.net

16
What definitions were crucial to further understanding?
mathoverflow.net

13
Integer but not Laurent sequences
mathoverflow.net

13
Why doesn't mathematics collapse even though humans quite often make mistakes in their proofs?
mathoverflow.net

12
About the definition of E8, and Rosenfeld's “Geometry of Lie groups”
mathoverflow.net

10
Fascinating moments: equivalent mathematical discoveries
mathoverflow.net

10
Open questions about posets
mathoverflow.net

10
Important open problems that have already been reduced to a finite but infeasible amount of computation
mathoverflow.net

10
A different avatar of the complexity of a graph
mathoverflow.net

10
Theorems that impeded progress
mathoverflow.net

10
Reference request: Grassmannian and Plucker coordinates in type B, C, D
mathoverflow.net

9
What is the amplituhedron?
mathoverflow.net

9
Double Counting: Motivic Edition
mathoverflow.net

8
Injectivity implies surjectivity
mathoverflow.net

8
Is there any positive integer sequence $c_{n+1}=\frac{c_n(c_n+n+d)}n$?
mathoverflow.net

8
Independent evidence for the classification of topological 4-manifolds?
mathoverflow.net

8
Bijective proof of an Abel-Hurwitz-type identity
mathoverflow.net

8
Accidental, unplanned breakthroughs in Mathematics
mathoverflow.net

8
Important formulas in Combinatorics
mathoverflow.net

7
Plucker relations in orthogonal Grassmannian
mathoverflow.net

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