Questions tagged [vector-bundles]
A continuously varying family of vector spaces of the same dimension over a topological space. If the vector spaces are one-dimensional, the term line bundle is used and has the associated tag line-bundles.
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global algebraic functions $\Gamma(T^{*}M)$ on the cotangent bundle of moduli space
Let $X\colon$ smooth projective curve,
$\mathcal{M}\colon $ moduli space of semistable higgs bundle of rank $r$ and with fixed determinat $\xi$, and
$H\colon \mathcal{M}\rightarrow W=\oplus_{i=2}^{r} ...
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Varieties satisfying the extension of vector bundles property
We know if we have a regular variety $X$ with $U$ an open sub-scheme such that $codim(X\setminus U)\geq 2$, then any reflexive sheaf has a unique extension from $U$ to $X$. My question is when a ...
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How to recognize a vector bundle?
Given a connected topological space $E$, under which conditions is it possible to find a subspace $B$ such that $E$ can be regarded as a (rank $n$) vector bundle over $B$?
Is it possible to find the ...
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Pull-back a section of a vector bundle
Let $M$ be a manifold of dimension $n$ and $\mathcal D$ be a distribution of dimension $n-1$. We consider the quotient bundle $TM/\mathcal D = \bigsqcup_{p \in M} T_pM/\mathcal D_p$ with the ...
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Characteristic classes in term of cocycles
Giving a vector (principal) bundle is equivalent to give a family of cocycles ${g_{\beta \alpha}: U_\alpha\cap U_\beta \to G}$ where $G$ is the structure group of the bundle.
Chern classes are ...
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Local triviality condition in vector bundles [closed]
Let $E$ and $M$ be smooth manifolds (of finite dimension, Hausdorff and second countable). Let $\pi:E\longrightarrow M$ be a surjective submersion such that:
$E_p:=\pi^{-1}(p)$ is a real vector space ...
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Dual of a specific coherent sheaf that is a vector bundle
Let's assume we have two short exact sequence of vector bundles on a smooth variety $X$ over a field. $l_1: 0\rightarrow V_1 \rightarrow V \rightarrow V_2 \rightarrow 0$ and $l_2: 0\rightarrow V_3 \...
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Can non-split extension be isomorphic to the split one as objects
Is it possible to have a non-split short exact sequences of vector bundles (on some smooth variety) $0\rightarrow V_1 \rightarrow V_2 \rightarrow V_3 \rightarrow 0$. Such that $V_2\cong V_1\oplus V_3$ ...
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Symplectic structure on the space of complexes of holomorphic vector bundles
Let $E\rightarrow X$ be a holomorphic vector bundle over a complex manifold. Denote by $Dol(E)$ the space of holomorphic structures on $E$. Fix any Hermitian metric $h$ on $E$ and denote by $\mathcal{...
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$2$-vector spaces and algebraic $2$-stacks
I am thinking about higher Artin stacks in the sense of Simpson, concretely I would like to calculate the dimension and compare these two cases:
$\mathfrak{X}_{1}=$ Higher linear stack classifying (...
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Curvature of a superconnection
Let $E\rightarrow X$ be a $\mathbb{Z}_2$-vector bundle (or superbundle for connoisseurs) and consider the superconnection
$$A=\nabla + B$$
where $\nabla$ is a connection on $E$ and $B\in\Gamma(End(E))^...
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Geometric intuition for $R[x,y]/ (x^2,y^2)$, kinematic second tangent bundle, and Wraith axiom
This is a sort of continuation of this question.
In synthetic differential geometry (SDG), we have $D\subset R$ comprised of the second order nilpotents. The Kock-Lawvere axiom (KL axiom) implies that ...
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Vector bundle defined by using divisors of very ample line bundle
Let $X$ be a smooth projective curve. Suppose that $L_1$ and $L_2$ are line bundles on $X$, and $L_1$ is very ample.
$\operatorname{Div}(s)$ denotes a divisor defined by a global section $s\in H^0(X,L)...
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The openness the set of $s\in \bigoplus H^0(C,K_{C}^{\otimes i})$ for which the spectral curve is irreducible and reduced
Let $C$ be smooth projective curve, $\mathcal{M}$ be the moduli space of semistable Higgs bundles, $H:\mathcal{M}\rightarrow W= \bigoplus H^0(C,K_{C}^{\otimes i})$ be the Hitchin map, and $\pi :C_s\...
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K-theory on finite-dimensional (possibly not finite) CW complexes
I am trying to understand why (at least my most elementary understanding of) topological K-theory breaks down for non-compact things (which I have seen asserted in various places). In particular, as ...
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Vector bundles on $\mathbf{P}^1$ and the Iwasawa decomposition
As everyone knows, every vector bundle on $\mathbf{P}^1$ splits as a direct sum of line bundles $\mathcal{O}(a_1)\oplus\cdots\oplus\mathcal{O}(a_n)$. This means that in the Weil-uniformisation ...
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Global algebraic function over the moduli space of semistable higgs bundles $\mathcal{M}$
Let $X$ be a smooth projective curve over $\mathbb{C}$, $\mathcal{M}$ be the moduli space of semistable higgs bundles, and $h: \mathcal{M}\rightarrow W=\bigoplus H^0(X,K_X^{\otimes{i}})$ be the ...
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Singularity of reproducing kernel for elliptic operator
Let $(M,g)$ be a smooth compact Riemannian manifold and dimension $2$, $\Gamma$ a smooth vector bundle over $M$, and suppose $L: W^{k,2}(\Gamma)\to W^{k-2,2}(\Gamma)$ is a second order strongly ...
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Fibers of Hitchin fibration are equidimensional
Let $X$ be a smooth projective curve over $\mathbb{C}$ of genus $g\ge 3$, $M$ be a moduli space of stable vector bundles on $X$ of rank $n\ge 2$ and degree $d$, $\mathcal{M}$ be a moduli space of ...
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Triviality of holomorphic vector bundles over $\mathbb{C}$
Let $E\longrightarrow\mathbb{C}$ be a holomorphic vector bundle.
I found two proofs that $E$ is trivial: one follows from Oka-Grauer principle (Theorem 5.3.1 in F. Forstneric, Stein Manifolds and ...
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Differences between induced vector fields on a smooth manifold and on a principal bundle
In the context of the connections on fibre bundle, I have found some difficulties trying to understand the fundamental vector field (my reference is Nakahara, but I'm having some problems with the ...
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Question on Harmonic maps between Riemannian manifolds
In Theory of harmonic maps, main goal is to find minimum of Dirichlet energy function which is defined as follows:
$$E(f):=\frac{1}{2}\int_M\|df\|^2dvol_g\qquad f:(M,g)\to(N,h).$$
In many Books such ...
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Extension of a holomorphic vector bundle on a nodal curve
I am reading a paper on holomorphic curves and stuck in an argument about extension of a given holomorphic vector bundle over a nodal curve.
Let $C$ be a nodal curve without closed componets and $E$ a ...
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The compactified Jacobian is birational to a $\mathbb{P}^1$-fibration over the Jacobian of normalization
Let $Y$ be an integral curve whose only singularity is one simple node at a point $y$, and
$\pi:X\rightarrow Y$ be the normalization with $\pi^{-1}(y)=\{x,z\}$. $J(X)$ is the Jacobian of $X$, and $\...
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Linearly dependent vector fields not spanned by fewer continuous vector fields
This is a follow-up to the question https://math.stackexchange.com/questions/3845080/linearly-dependent-vector-fields-that-are-not-spanned-by-fewer-continuous-vect, which attracted very little ...
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A question about pullbacks of $C^\infty_M$-modules
First, let me state a definition: Let $M$ be a smooth manifold and suppose $\mathcal{E}$ is a sheaf of $C^\infty_M$-modules. Given a point $x \in M$ let $I_x$ denote the vanishing ideal at $x$. We ...
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Fiber of the Hitchin map
Let $C$ be smooth projective curve, $\mathcal{M}$ be the moduli space of semistable Higgs bundles, $H:\mathcal{M}\rightarrow W= \bigoplus H^0(C,K_{C}^{\otimes i})$ be the Hitchin map, and $\pi :C_s\...
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lie algebra bundle and underlying vector bundle
Let $G$ be a connected reductive group over a field $k$. Let $E$ be a $G$-bundle, then we can form the adjoint bundle $ad(E)$ which is a Lie algebra bundle over $k$.
As a vector bundle it is trivial, ...
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Chern classes of a mapping torus vector bundle in terms of the construction data
Let $\pi:E\to X$ be a complex vector bundle*, and $f:E\to E$ a bundle isomorphism.
Consider the mapping torus
$$E(f) := \frac{E\times [0,1]}{E \times \{0\}\sim_f E \times \{1\}}$$
where the ...
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Non-isomorphic short exact sequences on isomorphic objects
$\DeclareMathOperator\Ext{Ext}\newcommand\SE{\mathrm{SE}}\newcommand\Def{\mathrm{Def}}$Assume $X$ is a smooth projective variety over a field. There are two non-isomorphic short exact sequence of ...
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Deformations of vector bundles and tubular neighborhood
I had a number of questions that are somewhat related to each other. I decided to post them altogether instead of separately. I'd appreciate any kinds of answers, ideas or sources regarding any of ...
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Describe $\mathcal{N}_{G(\mathbb{P}^1,\mathbb{P}^k)\mid G(\mathbb{P}^1,\mathbb{P}^n)}$ [from MSE]
Note: This question came from MSE, but since I've received some useful observations I posted it here. Post on MSE
Consider $1 \leq k < n$ positive integers, and denote by $G(\mathbb{P}^k,\mathbb{P}...
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Vanishing locus generic section $(\mathrm{sym}^2 \mathcal{R})(1)$
Let $n = 2m$ be an even integer and let $\mathcal{R}$ the tautological bundle on the Grassmannian $\mathrm{Gr}(2,n)$. I am looking for an explicit description of the degener
The bundle $(\mathrm{Sym}^...
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Definition of Hitchin map
This may be a dumb question.
$\mathcal{M}(r,d)$ is a coarse moduli scheme for semistable pairs $(E,\phi:E \rightarrow K_X \otimes E)$ of rank $r$, degree $d$ on a smooth projective curve $X$ over $\...
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Hitchin map and vector bundles
I've been learning a bit about automorphisms of moduli spaces of vector bundles and the Hitchin map.
I'm reading this paper of Indranil Biswas, Tomas L. Gomez, V. Munoz, and I have a problem about ...
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Derivative of the Bott-Chern forms
The Bott-Chern forms are constructed formally in Bismut's "Analytic Torsion and Holomorphic Determinant Bundle I" (page 74). This construction can be found as well in "Lectures on Arakelov Geometry" ...
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Relation between Bott-Chern forms and Second fundamental form
Given a short exact sequence of holomorphic Hermitian vector bundles
$$0\rightarrow F\rightarrow E\rightarrow G\rightarrow 0,$$
the second fundamental form measures the obstruction of $E\simeq F\oplus ...
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On the locality of the Lefschetz conditions
Given a smooth projective variety $X$ of dimension $\geq 3$ and an ample divisor $Y$. The pair satisfy the effective Lefschetz condition $Leff(X,Y)$. This implies that the category of vector bundles ...
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If two smooth manifolds are homeomorphic, then their stable tangent bundles are vector bundle isomorphic
I am currently reading Kervaire-Milnor's paper "Groups of Homotopy Spheres I", Annals of Mathematics, and I am trying to prove (or disprove) the following result. The more elementary the ...
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On definition of stable vector/Higgs bundle
Recall that the slope of a holomorphic vector bundle $\mathcal{E}$ over a smooth projective variety (or rather a compact Kähler manifold) $X$ is defined as
$\mu(\mathcal{E}) :=\frac{\operatorname{deg}(...
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$K_0$ of configuration of hyperplanes
Let $\ell_n$ where $n\geq 3$ be the configuration of $n$ lines in a plane, such that $n-1$ of them pass through a single point and the last one does not and it intersects rest of the $n-1$ lines. I'm ...
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Serre vanishing on one-point blow-ups
This is basically the last step of problem 5.3.7 in Huybrechts' Complex Geometry.
Let $X$ be a complex manifold, $x \in X$, $E$ a holomorphic vector bundle on $X$ and $L$ a positive line bundle. ...
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Riemannian version of topological $K$-theory
Let $X$ be a compact Hausdorff space.Put $Vec(X)$, the space of all real (or complex) vector bundles over $X$.We put also $Vec_g(X)$, the space of all Riemannian vector bundles over $X$, that is the ...
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A question on moduli space of Hitchin's equations
I am reading Hitchin's Self-Duality paper. In section 5 (page 85), he is trying to prove that $Dim H^1=12(g-1)$. In doing so, he defines an operator $d^*_2+d_1$, where $d^*_2$ and $d_1$ are given by
$...
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Koszul-Malgrange Holomorphic structure on a pullback bundle
I'm finding myself a little confused about Koszul-Malgrange holomorphic structures in a certain context.
Suppose $M$ is a complex manifold, $N$ is a smooth manifold with a smooth complex vector bundle ...
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Integrability condition for flat connections
I am reading Kobayashi's book "Differential geometry of complex vector bundles". More precisely, I am on section 2 of chapter 1, page 5.
Kobayashi is trying to prove that if $E$ is a vector ...
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Fubini-Study metric induced by submersion
The Fubini-Study metric $g:=g_{FS}$ is the unique $U(n+1)$-invariant
Riemannian metric on the complex projective space $\mathbb{CP}^{n}$ the complex projective space
which by $U(n+1)$-invariance can ...
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Serre-Swan theorem for infinite rank Frechet or Hilbert bundles?
Is there a version of Serre-Swan theorem for infinite rank Frechet or Hilbert bundles? If it existed, it would imply if $E\to X$ and $F\to X$ are infinite rank Frechet or Hilbert bundles over a smooth ...
2
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Vector field along an immersion whose covariant derivative is the differential
Let $(M,g)$ be a Riemannnian manifold and let $f:\Sigma\to M$ be a smooth immersion. Then the vector bundle $f^\ast TM\to\Sigma$ has a natural bundle metric and metric-compatible connection. Can one ...
58
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Why do Todd classes appear in Grothendieck-Riemann-Roch formula?
Suppose for some reason one would be expecting a formula of the kind
$$\mathop{\text{ch}}(f_!\mathcal F)\ =\ f_*(\mathop{\text{ch}}(\mathcal F)\cdot t_f)$$
valid in $H^*(Y)$ where
$f:X\to Y$ is a ...