Leray–Hirsch, the Thom Isomorphism, and Gysin Sequences
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1 · Prerequisites
Abstract Algebra
- Binary Operations, Monoids, Groups and Subgroups
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Algebraic Topology
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Homological Algebra
Linear Algebra
Number Theory
Real Analysis
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2 · Logical flowchart
3 · Items
Lemma
A global fiber basis trivializes Serre monodromy
Lemma
The Leray–Hirsch associated-graded isomorphism lifts without extension ambiguity
Theorem
Leray–Hirsch module isomorphism
Definition
Disk, sphere, and Thom spaces of a metric vector bundle
Proposition
Thom spaces of zero and trivial bundles
Lemma
Disk-pair cohomology over an arbitrary commutative ring
Definition
R-oriented vector bundle and orientation local system
Definition
Thom class by fiberwise normalization
Theorem
Thom isomorphism for a trivial oriented bundle
Lemma
Thom isomorphisms glue over two trivializing opens
Lemma
Thom isomorphism extends over a finite numerable trivializing cover
Lemma
General Thom isomorphism from the relative Serre spectral sequence
Theorem
Thom isomorphism for oriented vector bundles
Theorem
Naturality and uniqueness of Thom classes
Theorem
External-product and Whitney-sum formulas for Thom classes
Definition
Thom diagonal and zero-section collapse
Definition
Thom-defined Euler class of an oriented vector bundle
Definition
Gysin pushforward for an oriented zero section
Theorem
Gysin long exact sequence of an oriented sphere bundle
Proposition
Thom and Gysin constructions respect pullback and composition
Sources
- Miller, MIT 18.906 notes, proof of Theorem 33.5
- Miller, MIT 18.906 notes, Theorem 33.5
- Hatcher, Vector Bundles and K-Theory
- May, A Concise Course in Algebraic Topology, Chapter 23 §5
- Miller, MIT 18.906 notes, Lectures 34–35
- Miller, MIT 18.906 notes, Proposition 35.2
- Miller, MIT 18.906 notes, Lectures 26 and 35