Leray–Schauder degree
E518467
The Leray–Schauder degree is a topological invariant that generalizes the Brouwer degree to compact perturbations of the identity in infinite-dimensional Banach spaces, providing a powerful tool for proving existence of solutions to nonlinear equations.
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
nonlinear analysis tool
ⓘ
topological degree ⓘ topological invariant ⓘ |
| appliesTo |
compact perturbations of the identity
ⓘ
infinite-dimensional Banach spaces ⓘ maps in Banach spaces ⓘ |
| assumes | Fredholm-type structure in many applications ⓘ |
| codomain | integers ⓘ |
| comparedTo | Brouwer degree NERFINISHED ⓘ |
| definedFor | compact maps on open bounded subsets of Banach spaces ⓘ |
| domain | Banach space ⓘ |
| field |
functional analysis
ⓘ
nonlinear functional analysis ⓘ partial differential equations ⓘ topology ⓘ |
| generalizes | Brouwer degree NERFINISHED ⓘ |
| hasVariant |
degree for Fredholm maps of index zero
ⓘ
degree for condensing maps ⓘ |
| historicalPeriod | 20th century mathematics ⓘ |
| namedAfter |
Jean Leray
NERFINISHED
ⓘ
Julius Schauder NERFINISHED ⓘ |
| property |
coincides with Brouwer degree in finite dimensions
ⓘ
homotopy invariant ⓘ integer-valued ⓘ stable under compact perturbations ⓘ |
| relatedTo |
Leray–Schauder fixed point theorem
NERFINISHED
ⓘ
Schauder fixed point theorem ⓘ topological degree theory ⓘ |
| requires |
a priori bounds on solutions
ⓘ
compactness of the nonlinear part ⓘ |
| satisfies |
additivity property
ⓘ
excision property ⓘ homotopy invariance property ⓘ normalization property ⓘ |
| toolFor |
integral equations
ⓘ
nonlinear boundary value problems ⓘ nonlinear operator equations ⓘ |
| usedFor |
boundary value problems
ⓘ
elliptic partial differential equations ⓘ existence of solutions of nonlinear equations ⓘ fixed point problems ⓘ |
| usedIn |
continuation methods
ⓘ
degree-theoretic proofs of existence theorems ⓘ global bifurcation theory ⓘ |
Referenced by (1)
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