5,875 reputation
22365
bio website math.berkeley.edu/~cgerig
location UC Berkeley
age 26
visits member for 4 years, 7 months
seen 6 hours ago

After doing my BS in engineering physics (with experimental research on gravity), I started my PhD in experimental atomic physics. But I quit to do math, and am now a 4th year student of Michael Hutchings.


Aug
19
accepted Representing classes in *relative* homology by submanifolds
Aug
18
comment Representing classes in *relative* homology by submanifolds
Ah nice, excision allows Lefschetz duality to get rid of the reduced homology. But at the very end, we are applying the Pontryagin-Thom construction... does it really work for manifolds with boundary? It looks like I have to build language to handle cobordisms/framings with corners.
Aug
18
revised Representing classes in *relative* homology by submanifolds
added 32 characters in body
Aug
18
asked Representing classes in *relative* homology by submanifolds
Aug
7
reviewed Reject Possible lower bound in quantum many body system with non-local terms
Aug
7
awarded  Good Question
Aug
6
awarded  Nice Answer
Aug
5
awarded  Good Question
Aug
1
comment Non-degenerate periodic orbits in the boundary of Lefschetz fibration over a disk
Just a comment that might spark a thought: $\phi_\Omega$ is a symplectomorphism w.r.t. $\Omega$, and periodic orbits of period $p$ are fixed points of $\phi^p_\Omega$. For a generic time-dependent Hamiltonian $H$ on $\pi^{-1}(1)$, the perturbed map $\psi_H\circ \phi_\Omega$ has only nondegenerate fixed points (where $\psi_H$ is the time-1 flow of the Hamiltonian isotopy). However, we can't recast a change $\Omega\mapsto\Omega'$ as an existence of $H$, because $\psi_H\circ\phi_\Omega$ is still a symplectomorphism w.r.t. the original $\Omega$.
Jul
30
comment Witten's proof of Morse inequalities, question on eigenvalues?
This is all contained in the OP's link, and does not answer his question.
Jul
30
comment The term $H^1(N,A)^{G/N}$ in the inflation-restriction exact sequence
When in doubt, consult Ken Brown's Cohomology of Groups!
Jul
28
revised Witten's proof of Morse inequalities, question on eigenvalues?
added 47 characters in body
Jul
28
revised Witten's proof of Morse inequalities, question on eigenvalues?
added 10 characters in body
Jul
28
answered Witten's proof of Morse inequalities, question on eigenvalues?
Jul
26
comment Is there a generalization of homotopy groups to fractional dimensions
What is a half-dimensional sphere?
Jul
24
awarded  Popular Question
Jun
7
comment Perturbation of eigenvalues of some special matrices
I've quickly attempted an interpretation of the OP by adding some background, but this can be made much more precise by giving explicit examples of those "general results".
Jun
7
revised Perturbation of eigenvalues of some special matrices
my guess at the intended question (since it was closed otherwise)
Jun
2
comment Flux group of surfaces with genus $g\ge2$
.....Their paper not only gives the reference [3] of Kedra, Remarks on the Flux Group, but says precisely what part of this paper proves triviality (Theorem B). A surface of genus greater than 1 has nonzero Euler characteristic and is aspherical.
May
26
revised Nontrivial finite group with trivial cohomology in prescribed degree
added 171 characters in body