User Yuji Tachikawa

7 votes

2 answers

880 views

Cohomology of the classifying space of $Ss(4m)$

asked Sep 26, 2013 at 8:44

7 votes

0 answers

142 views

Explicit framed null bordism realizing $\eta\nu =0$ in stable homotopy group of spheres

asked Dec 7, 2023 at 14:41

4 votes

1 answer

621 views

Homomorphisms from binary polyhedral group to compact Lie groups

asked Jan 4, 2017 at 15:15

7 votes

1 answer

1k views

Ordinary cohomology groups of $(\mathbb{C}^3\times T^2)/\mathbb{Z}_k$ that I need for my string theory research

asked Jan 30, 2016 at 13:09

3 votes

1 answer

177 views

Explicit computations of Bismut-Cheeger eta form for $S^{2n}$ bundles

asked Mar 23, 2023 at 6:28

2 votes

0 answers

485 views

On quasi-modular forms with integer Fourier coefficients

asked Jun 20, 2022 at 13:24

20 votes

3 answers

681 views

Which elements of $H^2(M,\mathbb{Z}/2)$ are the $w_2(E)$ for a real bundle $E$?

asked Oct 19, 2019 at 13:32

26 votes

5 answers

10k views

What does the word "symplectic" mean?

asked Nov 7, 2010 at 11:43

11 votes

2 answers

299 views

Spectrum $E$ with $H^\bullet(E,\mathbb{Z}/2)=\mathcal{A}//\mathcal{A}(n)$

asked May 20, 2021 at 2:35

11 votes

3 answers

883 views

Are the rings $\mathbb{C}[X]/\langle X^2- c \mathrm{Tr}(X) X \rangle$ isomorphic when $c$ ranges over a neighborhood of 0?

asked Mar 5, 2020 at 2:12

8 votes

1 answer

750 views

Modular forms over $\mathbb{Z}$ vs modular forms with integral Fourier coefficients

asked Mar 10, 2021 at 5:06

6 votes

1 answer

366 views

Integral (co)homology of $SU/SO$

asked Nov 5, 2019 at 5:49

12 votes

1 answer

351 views

Unoriented bordism with twisted orientation

asked May 7, 2019 at 4:51

21 votes

3 answers

2k views

When is a coadjoint orbit an integrable system (in a weak sense explained below)?

asked Jan 12, 2012 at 3:57

5 votes

1 answer

277 views

Modular tensor category associated to an even integral lattice and the lattice automorphism

asked Apr 18, 2018 at 15:44

3 votes

1 answer

770 views

Do $G$-invariant non-degenerate quadratic forms come from $G$-invariant even lattices?

asked Apr 16, 2018 at 7:20

3 votes

1 answer

193 views

pushforward in non-multiplicative generalized cohomology theory

asked Nov 21, 2017 at 1:53

3 votes

0 answers

161 views

a universal module for group cohomology?

asked Dec 27, 2017 at 12:19

13 votes

1 answer

1k views

How should I formalize that there’s no canonical isomorphism between a finite Abelian group and its Pontryagin dual?

asked Oct 1, 2017 at 15:06

6 votes

0 answers

101 views

Squaring operation in KO theory

asked Aug 4, 2017 at 16:17

3 votes

1 answer

560 views

Twists of commutative Hopf algebras

asked Dec 15, 2016 at 13:56

13 votes

3 answers

1k views

Computation of $\pi_4$ of simple Lie groups

asked Jan 13, 2017 at 9:02

7 votes

2 answers

645 views

Value of the Chern-Simons functional for flat connections on $S^3/\Gamma$

asked Dec 28, 2016 at 11:48

1 vote

0 answers

51 views

Properties of pairing-reversing automorphisms of integral lattices

asked Aug 7, 2016 at 5:50

1 vote

1 answer

318 views

Sheets in Lie algebras are classified by the pair $(\mathfrak{l},O)$. How about sheets in Lie groups?

asked Dec 2, 2011 at 8:50

11 votes

1 answer

326 views

$\pi_1$ of the moduli of G-bundles on elliptic curves and the double affine braid group

asked Oct 8, 2015 at 6:56

10 votes

0 answers

638 views

On cyclic homology of Ginzburg's DG algebra

asked Jun 26, 2012 at 10:37

7 votes

3 answers

991 views

The relation of nilpotent orbits and simple singularities, for orbits smaller than subregular ones

asked Jan 20, 2012 at 14:55

6 votes

0 answers

1k views

Question on Atiyah-Patodi-Singer on $T^3$

asked Nov 22, 2014 at 14:54

33 votes

5 answers

3k views

How can I visualize the nontrivial element of $\pi_4(S^3)$ and $\pi_5(S^3)$ ?

asked Sep 11, 2010 at 3:28

Stack Exchange Network

59 Questions

Cohomology of the classifying space of $Ss(4m)$

Explicit framed null bordism realizing $\eta\nu =0$ in stable homotopy group of spheres

Homomorphisms from binary polyhedral group to compact Lie groups

Ordinary cohomology groups of $(\mathbb{C}^3\times T^2)/\mathbb{Z}_k$ that I need for my string theory research

Explicit computations of Bismut-Cheeger eta form for $S^{2n}$ bundles

On quasi-modular forms with integer Fourier coefficients

Which elements of $H^2(M,\mathbb{Z}/2)$ are the $w_2(E)$ for a real bundle $E$?

What does the word "symplectic" mean?

Spectrum $E$ with $H^\bullet(E,\mathbb{Z}/2)=\mathcal{A}//\mathcal{A}(n)$

Are the rings $\mathbb{C}[X]/\langle X^2- c \mathrm{Tr}(X) X \rangle$ isomorphic when $c$ ranges over a neighborhood of 0?

Modular forms over $\mathbb{Z}$ vs modular forms with integral Fourier coefficients

Integral (co)homology of $SU/SO$

Unoriented bordism with twisted orientation

When is a coadjoint orbit an integrable system (in a weak sense explained below)?

Modular tensor category associated to an even integral lattice and the lattice automorphism

Do $G$-invariant non-degenerate quadratic forms come from $G$-invariant even lattices?

pushforward in non-multiplicative generalized cohomology theory

a universal module for group cohomology?

How should I formalize that there’s no canonical isomorphism between a finite Abelian group and its Pontryagin dual?

Squaring operation in KO theory

Twists of commutative Hopf algebras

Computation of $\pi_4$ of simple Lie groups

Value of the Chern-Simons functional for flat connections on $S^3/\Gamma$

Properties of pairing-reversing automorphisms of integral lattices

Sheets in Lie algebras are classified by the pair $(\mathfrak{l},O)$. How about sheets in Lie groups?

$\pi_1$ of the moduli of G-bundles on elliptic curves and the double affine braid group

On cyclic homology of Ginzburg's DG algebra

The relation of nilpotent orbits and simple singularities, for orbits smaller than subregular ones

Question on Atiyah-Patodi-Singer on $T^3$

How can I visualize the nontrivial element of $\pi_4(S^3)$ and $\pi_5(S^3)$ ?