The weights tag has no wiki summary.
3
votes
1answer
250 views
“Weight-mondoromy” for open varieties
Suppose that $X/\mathbb{Q}_p$ is a smooth, projective variety, and choose a prime $\ell\neq p$. Then the weight-monodromy conjecture says that the graded pieces $\mathrm{Gr}_k^M$ of the monodromy ...
2
votes
1answer
134 views
Weight multiplicities for some particular representations of SO(2m).
I am looking for explicit formulas for the weight multiplicities of some particular irreducible representations of $SO(2m)$.
It is possible that they have been already computed; in this case I will ...
1
vote
0answers
58 views
Is semistability of smooth Weil sheaf preserved under tensor product?
Let $X_0$ be a smooth, geometrically connected scheme over $\mathbb{F}_q$. As usual, let $\tau : \bar{\mathbb{Q}}_{\ell} \simeq \mathbb{C}$ be a fixed isomorphism. Let $\mathcal{C}$ be the category of ...
6
votes
2answers
368 views
Hodge structure versus Weight structure
This is a naive question.
One is told that, somehow, Hodge theory for varieties over complex numbers, is an analog of weight theory for varities over finite fields. In weight theory, one considers ...
3
votes
0answers
237 views
Tiling a rectangle with weighted cells (min-max problem)
I have been struggling with a research problem. The problem can be formalized as follows:
Given a $n\times m$ matrix $A$ containing cells with non-negative integer values, partition it in $J$ ...
11
votes
2answers
400 views
A_infinity structure on cohomology and the weight filtration
Let $X$ be a complex algebraic variety. The rational cohomology of $X(\mathbb{C})$ carries a canonical filtration called the weight filtration. It also carries a canonical equivalence class of ...
4
votes
2answers
297 views
Weights of restricted modules of some Cartan type Lie algebras
Let $L$ be a simple Lie algebra of Cartan type of absolute toral rank 2 over an algebraically closed field $\mathbb{F}$ of characteristic $p\geq 5$.
Denote by $L_{[p]} $ the minimal $p$-envelope of ...
1
vote
0answers
153 views
Universal Correlation measure — ranking correlations
I have time series data of experimental observations for two related processes. I want to measure correlation for use in further analysis.
Correlation of the series changes over time and across ...
1
vote
1answer
83 views
weighted to centre mean
I'm not even sure if what I want to do is a good idea but I figure I'll experiment and see.
I have two predicted ratings in the range of 1-5 based on two different algorithms for predicting movie ...
2
votes
1answer
350 views
Which (reducible) projective varieties could be presented as 'relatively smooth' hyperplane sections of irreducible (normal) ones?
Are there any restrictions known on a (complex reducible) projective variety $Y$ that can be presented as $Z\cap H$, where $Z$ is a normal (or just irreducible) closed subvariety of a smooth ...
1
vote
0answers
125 views
A Weyl invariance constructed from Clebsch-Gordan Coefficients.
Let $V$ and $\tilde{V}$ be irreducible representations of SU(N) with tensor decomposition:
\begin{equation}
V \otimes \tilde{V} = \bigoplus_i U_i
\end{equation}
\noindent were $U_i$ are also irreps ...
2
votes
0answers
236 views
Does Artin's vanishing hold for '$E_2$-weight pieces' for (torsion) cohomology of affine varieties?
Let $X$ be an affine variety of dimension $n$ (say, over complex numbers). Then Artin's vanishing theorem yields: both singular and etale cohomology $H^i(X):=H^i(X,\mathbb{Z}/l\mathbb{Z})=0$ for ...
6
votes
1answer
416 views
Does intersection pairing on `$IH^*(X)$` agree with cup-product on `$H^*(X)$`?
Let $X$ be a proper singular variety over $k=\overline{\mathbb F}_p,$ irreducible of dimension $d.$ Let $H^*(X)$ and $IH^*(X)$ be the $l$-adic cohomology groups and $l$-adic intersection cohomology ...
5
votes
4answers
451 views
Smooth in codimension-k and the weight filtration
Let $X$ be an algebraic variety. Then $H_{et}^k(X)$ has a filtration whose associated graded pieces are labeled by "weights", certain integers between $0$ and $2k$. If $X$ is smooth, then the weights ...
1
vote
2answers
211 views
Maximizing the ratio of (weigthed sum)/sqrt(variance_weighted_sum)
I have a weighted sum,
weighted sum = w1*mu1 + (1-w1)*mu2
with
variance weighted sum = (w1^2)*var1 + ((1-w1)^2)*var2 + 2*w1*(1-w1)*cov
in which
mu1 = mean 1;
mu2 = mean 2;
var1 = variance for ...
2
votes
0answers
167 views
A Hodge substructure with ''nice' weight factors that does not correspond to a mixed submotif?
Suppose that we have a mixed motif $M$ with only two (subsequent) weights, and have a subobject for each weight factor. How we can control whether there exists a submotif of $M$ with these two ...
3
votes
1answer
657 views
Do Deligne's decalage and two filtrations for mixed Hodge complexes have a conceptual explanation?
As far as I understood, there are two way to assign weights to a mixed Hodge complex (a way that does not depend on shifts, and another one that does). There is a clever way to relate these to ways ...
6
votes
0answers
268 views
Cohomology of Zariski neighborhoods
Do there exist smooth compact (=complete) connected complex algebraic varieties $X\subset Y$ and a Zariski neighborhood $U$ of $X$ in $Y$ such that the image of $H^{\ast}(U,\mathbf{Z})$ in ...
7
votes
2answers
582 views
Which statements in section 5 of BBD will fail if we consider $\mathbb{Q}_l$-adic sheaves there?
A stupid question: which statements in section 5 of BBD will fail if we replace $\overline{\mathbb{Q}_l}$-sheaves by just $\mathbb{Q}_l$-ones? I am especially interested in Proposition 5.1.15.
BBD = ...
5
votes
2answers
655 views
In what setting does one usually define mixed sheaves and weights for them?
In BBD mixed sheaves and weights for them were only defined for ($\overline{\mathbb{Q}_l}$-)sheaves over a variety $X_0$ defined over a finite field $F$. Weights start to behave better when one ...
