Questions tagged [tangent-bundle]
The tangent $TX$ of a smooth (real or complex) manifold is defined as disjoint union of all the tangent space at the points of $X$. This the first and natural example of vector bundle.
423 questions
-3 votes
0 answers
52 views
On vector field. [closed]
For vector field $X, Y$ and one-form $\omega$ with its value in $T_M$, why does the identity $[\omega, \omega](X, Y) = \frac{1}{2}\{[\omega(X), \omega(Y)] - [\omega(Y), \omega(X)]\}$ hold?
2 votes
0 answers
48 views
Patching connections with partitions of unity preserves torsion?
In Section 10.2 of Loring W. Tu’s Differential Geometry: Connections, Curvature, and Characteristic Classes, he explains how to patch connections on a vector bundle using partitions of unity. He uses ...
7 votes
1 answer
172 views
The tangent bundle of $\mathbb{S}^{n}$ is a connected manifold
I have this exercise: Consider the map $$ F: \mathbb{R}^{n+1} \times \mathbb{R}^{n+1} \to \mathbb{R}^{2},\ \ F(p,q) = (||p||^{2}, \left<p,q\right>). $$ Prove that $F$ is differentiable and $(1,...
8 votes
0 answers
140 views
Explicit proof that tangent bundle of the 2-sphere, TS^2, is parallelizable
Let $T S^2$ denote the tangent bundle of the 2-sphere $S^2 = \{x \in \mathbb{R}^3 : \|x\|=1\}$. In this paper, Fodor proves that $T S^2$ is parallelizable, using machinery that I do not understand ---...
0 votes
1 answer
92 views
Vector field tangent to hyperbolic circle
Let $X$ be the geodesic vector field in $T^{1}\mathbb{R}^{2}$ and let $Y=(0,1)$ be the constant vector field on the fiber component of $T^{1}\mathbb{R}^{2}$. Then, integral lines of the vector field $...
1 vote
1 answer
140 views
Construction of the topology on the tangent space of a smooth manifold $M$ in Michael Spivak way with curves
Like the title suggest, I'm having trouble in Michael Spivak first book about differential geometry, more specificaly chapter 3. An important note is that in his book, Spivak say that a manifold is a ...
0 votes
1 answer
63 views
Splitting of the tangent bundle of a disk bundle
For each $x\in S^3$, where $S^3$ is identified with the unit quaternions, let $f^x_{h,l}:\mathbb{H}\rightarrow \mathbb{H}$ be the transformation $f^x_{h,l}(v)=x^hvx^h$. Taking the open sets $U_1=S^4\...
0 votes
0 answers
50 views
Tangent bundle and inmersion
In a certain exercise I have been asked to show that, given a smooth manifold $M$, the vector field $X: M \rightarrow TM$ such that $\forall p \in M$ the field gives the zero vector in $T_pM$ is an ...
0 votes
0 answers
84 views
Orientable surface with non-vanishing vector field Is Parallelizable
Let $M$ be a 2-dimensional smooth, orientable manifold in which there is a non-vanishing global vector field, that is an $X\in\mathfrak{X}(M)$ such that $X(p)\neq0,\,\forall p\in M$. Show that $M$ is ...
1 vote
1 answer
89 views
Vertical bundle is the square of the original bundle
Let $p:M\to X$ be a smooth vector bundle of rank $n$, and let $\tau_M$ be the tangent bundle of $M$. Since the bundle is smooth, we can take the derivative at any point of $M$, $d_mp: T_mM\to T_{p(m)}...
5 votes
2 answers
200 views
Is the tangent bundle of an almost complex manifold also almost complex?
Let $X$ be a smooth manifold with an almost complex structure $J$. Then does $J$ induces an almost complex structure (thus, a map $TTX\to TTX$) on the tangent bundle $TX$, canonically so that the zero ...
1 vote
2 answers
99 views
Why $T_{(x,0)}(NM) = T_{(x,0)}M_0 \oplus T_{(x,0)}(N_xM)$? (Theorem 6.24, Introduction to Smooth Manifolds, John Lee)
I'm working through the proof of the Tubular Neighborhood Theorem and came across this decomposition of the tangent space of the normal bundle: $$T_{(x,0)}(NM) = T_{(x,0)}M_0 \oplus T_{(x,0)}(N_xM).$$ ...
0 votes
1 answer
113 views
Zero locus of a global section of $T_{\mathbb{P}^n}(-1)$
Setup. Consider the $n$-dimensional complex projective space $\mathbb{P}^n$, and consider the Euler sequence $$ 0\to \mathcal{O}_{\mathbb{P}^n}(-1) \to \mathcal{O}_{\mathbb{P}^n}^{\oplus n+1} \to T_{\...
1 vote
0 answers
125 views
Tangent space of the real projective space.
So I've confused myself on calculating the tangent space of $\mathbb{P}^n$. The definition of a tangent space I am working with is the set of all derivatives at $0$ of a smooth curve at a point $p$. ...
1 vote
1 answer
83 views
Implicit (non embedded) tangent spaces and tangent bundles in physics
I'm working through differential geometry specifically as it applies to general relativity. Many of the texts or presenters make the assertion that we always use an implicit or non embedded ...