0
votes
2answers
335 views
Domains of homolorphy in the complex plane
There is a proof of Mittag-Leffler's theorem with an explicit construction of a holomorphic function with the prescribed poles with prescribed order and residues, for a countable d …
1
vote
2answers
562 views
Is a proper quotient map closed ?
I am trying to produce closed quotient maps, as they allow a good way of creating saturated open sets (as in this question).
A map $f:X\rightarrow Y$is called proper, iff preimage …
4
votes
1answer
263 views
Associativity with infinite nesting
I was trying to understand the Eilenberg-Mazur swindle (which I learned about here) especially as it could be used to show that if $A, B$ are compact (topological) $n$-manifolds wh …
3
votes
1answer
176 views
Image of composite morphisms
I am new to categories and I found in a book that it is possible to construct a category in which the following are true: there exist morphisms $f:A \to B$ and $g:B \to C$, and mon …
4
votes
0answers
439 views
Finite Idempotent Semirings (Dioids)
How many finite idempotent semirings (dioids) are there of order n?
And how many have an addition operation that coincides with a maximum operation for some ordering of the elemen …
1
vote
2answers
364 views
Implicit derivative?
If we have function $y=L(x_1,x_2,x_3,...,x_n)$, and function $z=R(x_1,x_2,x_3,...,x_n)$. How to compute the derivative $\frac{dy}{dz}$?
Shall I do $\frac{dy}{dz} = \sup_{g\in \Re^ …
0
votes
0answers
134 views
minimal count of linear dependent columns in matrix tensor product
Hello, all!
I have two matrices $\underset{n \times m}{A}$ and $\underset{t \times l}{B}$ over some extension field $GF(2^r)$: $n < m$ and $t < l$. For $A$ minimum count of …
asked Mar 12 2011 at 8:56
spk
6
votes
2answers
629 views
Sperner’s theorem and “pushing shadows around”
To head off any confusion: I'm talking about the extremal-combinatorics Sperner's theorem, bounding the sizes of antichains in a Boolean lattice.
So the "canonical proof" of this …
4
votes
2answers
702 views
Is the inertia stack of a Deligne-Mumford stack always finite?
Let X be a DM stack over a field k. We follow the definition in Laumon and Moret-Bailly's book, so that its diagonal is quasi-compact (and hence diagonal is of finite type). Then i …
1
vote
0answers
250 views
Ring Theory (indecomposable) [closed]
Show that a ring $R$ is local if and only if every principal left $R$-module is indecomposable.
3
votes
1answer
187 views
Adams graded parts of rational K-theory of a number field.
Let $F$ be a number field and $r_{1}$ and $r_{2}$ the numbers of real and pairs of complex embeddings respectively of $F$. Then Borel computed that for $n\geq 2$
$$
K_{n}(F)_{\ma …
1
vote
0answers
249 views
Map Transformation to Force Convergence to Unique Fixed Point
Is there a transformation $\mathcal{T}$ of maps $\mathbb{R}_{{\geq}0}^{n} \rightarrow \mathbb{R}_{{\geq}0}^{n}$ with the following property?
If a map $F : \mathbb{R}_{{\geq}0}^{n …
12
votes
0answers
398 views
How much has been written down about Deligne’s geometric approach to the order formula for a finite group of Lie type?
This is a follow-up to a recent mathoverflow question
34387
about computing the orders of finite unitary groups and the comments made there.
Between 1955 (Chevalley's Tohoku pape …
6
votes
1answer
226 views
Why do non-equioriented A<sub>n</sub> quivers have singularities identical to the singularities of Schubert varieties?
In the general case, quiver cycles are of the form of orbit closures of $GL\cdot V_{\vec{r}}$, where $GL= \prod_{i=0}^n GL_{r_i}$ is the possible changes of basis on all of the vec …
4
votes
5answers
657 views
Quantum Computing Complexity?
After reading a recent post on Church's Thesis, I ran into Turing-Church's Strong Thesis, that may be potentially disproven by advances in Quantum Computing. Does anyone know of a …
