1
vote
0answers
45 views
Classical parabolic theory (PDEs)
I am reading an articule(http://link.springer.com/content/pdf/10.1007%2Fs00028-010-0085-8.pdf) so I almost done but I dont understand the next argument is in the page 8 "It is kno …
1
vote
2answers
67 views
Incremental entropy computation
After a quick internet search I found no method for incremental entropy computation.
Question 1
Let $\{x_i\}_{i=1}^n$ and $\{x_i\}_{i=1+n}^{n+m}$ be two samples and let $S_i^j:= …
0
votes
0answers
73 views
smooth complete intersection
Hi,
I have been dealing with a problem and I could not find any tools to attack it. The problem is the following,
What extra conditions do I need to show that an affine smooth c …
0
votes
0answers
69 views
Substitution in a PC theorem [closed]
I am looking for a rigorous (meta)proof of "if A is a theorem of the propositional calculus, then so is the formula obtained by replacing a variable in A by any formula".
2
votes
1answer
93 views
Cauchy-Schwarz inequality for bilinear forms valued in an abstract vector space
I previously posted this question on Math.SE but didn't receive an answer. It is perhaps a little vague; part of what I want to know is what question I should ask.
First, conside …
1
vote
1answer
120 views
Why is the base change functor faithful
Let $L/k$ be a field extension of algebraically closed fields of characteristic zero. Let $U$ be a smooth quasi-projective variety over $k$.
I am trying to understand why the base …
-3
votes
0answers
152 views
And old hat with a new plume [closed]
The story of the blue-eyed islanders is well known, I assume.
http://mathoverflow.net/questions/29323/math-puzzles-for-dinner-closed
http://terrytao.wordpress.com/2008/02/05/the-bl …
2
votes
1answer
84 views
Correspondence between fractal sets and trees
In Hillel Furstenberg's series lectures on ergodic theory in fractal geometry, he mentioned his search on finding a one-to-one correspondence between fractal sets and trees, howeve …
0
votes
1answer
83 views
Subspace generated by positive vectors
Hi everyone, first of all i must admit i'm very familiar with quadratic forms and positive subspaces, so i'm sorry if my question is too trivial. So, here's my problem:
Let $L$ be …
1
vote
0answers
36 views
centralizer of p-subgroups in almost simple groups of characteristic p
Suppose $G$ is an almost simple group with normal simple group $S$. Suppose also that $S$ is
of Lie type of characteristic $p$. If $P$ is a sylow $p$-subgroup $S$, we know that $C_ …
2
votes
0answers
60 views
Normal abelian subgroups in p-groups
Given a group $G$, we denote by $T(G)$ the subgroup generated by all (maximal) normal abelian subgroups of $G$.
Let define the series $(T_i(G))$ by $T_0(G)=1$ and $T_{i+1}(G)/T_i( …
4
votes
1answer
123 views
Topological characterisation for a (closed irreducible) hyperbolic 3-manifold
Is there a topological characterisation of what a (closed irreducible) hyperbolic 3-manifold is? I don't know any Riemannian geometry and still want to understand what an exception …
3
votes
1answer
51 views
when is an algebra map conjugate to a star algebra map
Take a (unital) algebra map $f:A\to B$ between two unital C* algebras - not necessarily star preserving. Under what circumstances is there a $b\in B$ so that $g(a)=b\ f(a)\ b^{-1}$ …
1
vote
1answer
63 views
metric scaling for an inequality
I read a lemma 1.12 in Tobias H.Colding's paper "Ricci curvature and volume convergence"."Suppose that $Ri{c_{{M^n}}} \ge \left( {n - 1} \right)\Lambda {R^{ - 2}}$,p and $q \in M$ …
1
vote
1answer
83 views
Tangent space to positive oriented Grassmannians
Let $L$ be a real vector space of dimension 22 and $q$ a quadratic form on $L$ of signature $(3,19)$.
Let $V\subset L$ be a positive oriented subspace of dimension 2 and $G^{po}(2 …
