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6 votes
0 answers
197 views

Regarding a proof in the surgery theorem by Gromov and Lawson

I have a question regarding a proof in the article The classification of simply connected manifolds of positive scalar curvature written by Gromov and Lawson. The precise reference is: Gromov, ...
user12390's user avatar
  • 386
4 votes
0 answers
109 views

Is the heat semigroup on a manifold the limit of the heat semigroups associated to a compact exhaustion?

Let $M$ be a paracompact Riemannian manifold, and $E \to M$ a Hermitian vector bundle endowed with a Hermitian connection $\nabla$. Write $M$ as an exhaustion $\bigcup _{j \ge 0} U_j$ with relatively ...
Alex M.'s user avatar
  • 5,407
4 votes
0 answers
74 views

Determinant twist and $Pin _{\pm}$ structure on $4k$-dimensional bundles [Reference request]

Consider the automorphism $\varphi$ of $O(2n)$ given by $\varphi (A)=det(A)\cdot A$. The induced map in cohomology $H^*(BO(2n))$ sends $w_2$ to $w_2+(n+1)w_1^2$ (a proof is given at the end of the ...
user43326's user avatar
  • 3,051
3 votes
0 answers
157 views

$N$th-order approximation of point stabilizing diffeomorphisms by $N$th-order jet group?

NOTE: migrated from math SE. I was wondering if ever higher jet groups of frames on a (possibly pseudo) Riemannian manifold $M$ approximate the point stabilizing subgroup of diffeomorphisms on $M$ as ...
R. Rankin's user avatar
  • 250
3 votes
0 answers
283 views

Manifolds and Riemannian geometry with a bundle viewpoint

I was wondering if there are any books that builds the theory on manifolds and Riemannian geometry, but at the same time treats these subjects in the general case of bundles (similar to Jeffery Lee's ...
Master.AKA's user avatar
3 votes
0 answers
201 views

The heat kernel in Hermitian bundles over Riemannian manifolds

In "Heat Kernels and Dirac Operators" by Berline, Getzler and Vergne, the authors construct a (unique) heat kernel associated to any generalized Laplacian in a vector bundle over a Riemannian manifold....
Alex M.'s user avatar
  • 5,407
2 votes
0 answers
411 views

Parallel transport on a vector bundle : expansion of the correspondance between normal and tubular coordinates

Let $(M, g^{TM})$ be a Riemannian manifold of dimension $n$. Let $X \subset M$ be a submanifold of dimension $n$ with boundary $\partial X$. Then we have a splitting of the tangent bundle $$TM \vert_{\...
hseldon39's user avatar
2 votes
0 answers
192 views

Submanifold of Lie group whose tangent bundle is "almost" left-invariant

Let $G$ be a Lie group equipped with a left-invariant Riemannian metric, and let $M$ be a submanifold of $G$ containing the identity $e\in G$. It is not difficult to show that, if the tangent bundle $...
Matteo Raffaelli's user avatar
2 votes
0 answers
35 views

Can one extend a Hermitian bundle from a compact manifold with boundary to its Riemannian double?

Let $M$ be a compact Riemannian manifold with boundary, and let $E \to M$ be a Hermitian vector bundle, endowed with a compatible connection. Let $\tilde M$ be a Riemannian double of $M$. Does $E$ ...
Alex M.'s user avatar
  • 5,407
2 votes
0 answers
68 views

Hypoellipticity or parabolic regularity for vector bundles

Let $E \to M$ be a Hermitian vector bundle (of finite rank) over a Riemannian manifold (not necessarily compact). Let $H : \Gamma(E) \to \Gamma(E)$ be a differential operator with smooth coefficients ...
Alex M.'s user avatar
  • 5,407
2 votes
0 answers
95 views

Vector bundle endomorphism diffeomorphism invariant?

Let's say we have a vector bundle $V$ on a compact Riemannian manifold $M$ (of dimension $m$, with metric $g$). Given a differential operator $P$, acting on the sections of $V$, of the form: $$P = \...
phydev's user avatar
  • 91
2 votes
0 answers
197 views

Existence of a certain kind of compact spin manifold with boundary

For a compact spin Riemannian manifold $(M^n,g)$ without boundary, $n \not\equiv 3\mod 4$, it is well-known that the Dirac operator associated with a fixed spin structure $S\rightarrow M$ has real, ...
M. L. Nguyen's user avatar
2 votes
0 answers
250 views

Equivariant vector bundle structure on the tangent bundle of compact Riemann surfaces with non trivial action on the base space,

Let $M_{g}$ be the compact Riemann surface with $g\geq 2$. Is there an infinit group $G$ with an equivariant action on the pair $(TM_{g}, M_{g})$ such that the action on the fibers preserves the inner ...
Ali Taghavi's user avatar
1 vote
0 answers
632 views

Covariant Derivative of sections of a pullback bundle

Suppose that we have two smooth manifolds $M$ and $N$ and a smooth mapping $\phi : M \rightarrow N$. The Differential of that smooth mapping induces a bundle map $D\phi : TM \rightarrow TM$ between ...
shuhalo's user avatar
  • 5,327
1 vote
0 answers
225 views

Extending fibre metrics of submanifolds to Riemannian metrics

Let $M$ be a smooth manifold and $S\subseteq M$ a properly embedded smooth submanifold. Suppose that we have a fibre metric on $TM|_S$, i.e. a positive definite real inner-product on $T_pM$ for all $p\...
user115357's user avatar
1 vote
0 answers
180 views

Continuity of a convex function on a vector bundle

Consider the rank-${n \choose m}$ vector bundle $\pi\colon E:=\bigwedge^m(TN)\to N$ over a smooth Finsler manifold $N$ and equip each fibre $E_q := \pi^{-1}(q)$ with a norm that depends smoothly on $q\...
Sven Pistre's user avatar
1 vote
0 answers
1k views

Splitting Short exact sequences of vector bundle with connection

Let $F\to M$ be a vector bundle and $E\subseteq F$ a subbundle. Suposse that $\nabla$ is a connection on $F$ s.t. preserves $E$, i.e. $\nabla_X(e)\in \Gamma E \quad \forall e\in \Gamma E, \ X\in\Gamma ...
Miquel's user avatar
  • 11