2,984 reputation
1624
bio website simpletonsymposium.wordpress.…
location Evanston, IL
age 23
visits member for 4 years
seen yesterday

I'm a first-year grad student at Northwestern interested in homotopy theory.


Sep
30
awarded  Yearling
Aug
2
awarded  Notable Question
Jul
2
awarded  Curious
Jun
26
awarded  Enlightened
Jun
26
awarded  Nice Answer
May
22
comment Universe cardinals and models for ZFC
@tetori: thanks. So the idea is that if $V_\kappa$ models second-order ZFC, then every chain of ordinals of length less than $\kappa$ is the image of a function, so $\kappa$ must be regular. Whereas if $V_\kappa$ just models first-order ZFC, you could evade regularity of $\kappa$ by somehow blocking all these functions from being definable in $V_\kappa$. Correct?
May
22
comment Universe cardinals and models for ZFC
Thanks, this answers my question! By the way, can you take arbitrary (longer than $\omega$) unions of chains of submodels?
May
22
accepted Universe cardinals and models for ZFC
May
22
asked Universe cardinals and models for ZFC
Feb
9
awarded  Enlightened
Feb
9
awarded  Nice Answer
Oct
17
comment Sullivan model of the odd sphere
You're right, but $V = \Lambda^1 V$ has degree $2n+1$, by definition. You can pick the grading on the vector space to begin with, and then apply the exterior algebra construction.
Sep
30
awarded  Yearling
Jul
16
comment Homology of the Klein Bottle
@leo: Thanks, fixed!
Jul
16
revised Homology of the Klein Bottle
fixed image
Jul
16
comment singular (co)homology over various fields of same characteristic
Right. For example, if you have $p$-torsion in your integral homology and you're picking a field for your coefficients, you won't see that $p$-torsion unless your field has characteristic $p$.
Jul
14
answered singular (co)homology over various fields of same characteristic
Jul
8
reviewed Approve suggested edit on Work to pump water out of a tank with radius $10$
Jul
7
answered $\pi_0$ in the long exact sequence of a fibration and quaternionic projective space
Jul
4
revised Contractibility vs. G-contractibility
added a cool example