
COMPACT LIE GROUPS Contents 1. Smooth Manifolds and Maps 1
... Definition 1.3. An atlas for a manifold M is a collection of charts such that every point in M is in the coordinate domain for some chart. Atlases are a structure to describe the entire manifold in terms of charts. It is a slight but common abuse of terminology to speak of a manifold’s being covered ...
... Definition 1.3. An atlas for a manifold M is a collection of charts such that every point in M is in the coordinate domain for some chart. Atlases are a structure to describe the entire manifold in terms of charts. It is a slight but common abuse of terminology to speak of a manifold’s being covered ...
Topology Semester II, 2015–16
... Question 1. Show that if a topological space X has a countable basis {Bn }, then every basis C of X contains a countable basis for X. Answer. Let B := {Bn | n ∈ N} be a basis for the topological space X. Since C is a basis of X, for every m ∈ N there is an element C ∈ C such that C ⊂ Bm . Similarly, ...
... Question 1. Show that if a topological space X has a countable basis {Bn }, then every basis C of X contains a countable basis for X. Answer. Let B := {Bn | n ∈ N} be a basis for the topological space X. Since C is a basis of X, for every m ∈ N there is an element C ∈ C such that C ⊂ Bm . Similarly, ...
Introduction to Index Theory Notes
... The formula only defines ck (E) as a form of degree 2k, but in fact the cohomology class of this form is independent of the choice of connection. If the complex bundle E has rank n, one obtains n different characteristic classes (unless one counts c0 (E) = 1). The total Chern class c (E) is the clas ...
... The formula only defines ck (E) as a form of degree 2k, but in fact the cohomology class of this form is independent of the choice of connection. If the complex bundle E has rank n, one obtains n different characteristic classes (unless one counts c0 (E) = 1). The total Chern class c (E) is the clas ...
A BORDISM APPROACH TO STRING TOPOLOGY 1. Introduction
... Hilbert manifolds. Let us point out that three different types of free loop spaces are used in the mathematical literature: - Spaces of continuous loops ([7] for example), - Spaces of smooth loops, they are Fréchet manifolds but not Hilbert manifolds ([5] for some details), - Spaces of Sobolev clas ...
... Hilbert manifolds. Let us point out that three different types of free loop spaces are used in the mathematical literature: - Spaces of continuous loops ([7] for example), - Spaces of smooth loops, they are Fréchet manifolds but not Hilbert manifolds ([5] for some details), - Spaces of Sobolev clas ...
Topology Exam 1 Study Guide (A.) Know precise definitions of the
... (c) Jordan Curve Theorem. (What is the statement? What functions are useful in proving the theorem? How do you prove those functions are well-defined, continuous, etc.?) (d) Sperner’s Lemma. (What is the statement? What theorems are useful in proving it?) (e) Invariance of Dimension. (What is the st ...
... (c) Jordan Curve Theorem. (What is the statement? What functions are useful in proving the theorem? How do you prove those functions are well-defined, continuous, etc.?) (d) Sperner’s Lemma. (What is the statement? What theorems are useful in proving it?) (e) Invariance of Dimension. (What is the st ...
Orientability

In mathematics, orientability is a property of surfaces in Euclidean space that measures whether it is possible to make a consistent choice of surface normal vector at every point. A choice of surface normal allows one to use the right-hand rule to define a ""clockwise"" direction of loops in the surface, as needed by Stokes' theorem for instance. More generally, orientability of an abstract surface, or manifold, measures whether one can consistently choose a ""clockwise"" orientation for all loops in the manifold. Equivalently, a surface is orientable if a two-dimensional figure such as 20px in the space cannot be moved (continuously) around the space and back to where it started so that it looks like its own mirror image 20px.The notion of orientability can be generalised to higher-dimensional manifolds as well. A manifold is orientable if it has a consistent choice of orientation, and a connected orientable manifold has exactly two different possible orientations. In this setting, various equivalent formulations of orientability can be given, depending on the desired application and level of generality. Formulations applicable to general topological manifolds often employ methods of homology theory, whereas for differentiable manifolds more structure is present, allowing a formulation in terms of differential forms. An important generalization of the notion of orientability of a space is that of orientability of a family of spaces parameterized by some other space (a fiber bundle) for which an orientation must be selected in each of the spaces which varies continuously with respect to changes in the parameter values.