Refine
Year of publication
Document Type
- Article (1033)
- Monograph/Edited Volume (424)
- Doctoral Thesis (148)
- Preprint (95)
- Other (46)
- Review (16)
- Postprint (15)
- Conference Proceeding (8)
- Master's Thesis (7)
- Part of a Book (3)
Is part of the Bibliography
- yes (1798) (remove)
Keywords
- data assimilation (10)
- regularization (8)
- Cauchy problem (7)
- Fredholm property (7)
- cluster expansion (7)
- discrepancy principle (7)
- Bayesian inference (6)
- index (6)
- reciprocal class (6)
- Dirac operator (5)
Institute
- Institut für Mathematik (1798) (remove)
Valuations of Terms
(2003)
Let tau be a type of algebras. There are several commonly used measurements of the complexity of terms of type tau, including the depth or height of a term and the number of variable symbols appearing in a term. In this paper we formalize these various measurements, by defining a complexity or valuation mapping on terms. A valuation of terms is thus a mapping from the absolutely free term algebra of type tau into another algebra of the same type on which an order relation is defined. We develop the interconnections between such term valuations and the equational theory of Universal Algebra. The collection of all varieties of a given type forms a complete lattice which is very complex and difficult to study; valuations of terms offer a new method to study complete sublattices of this lattice
We introduce a differential topological invariant for compact differentiable manifolds by counting the small eigenvalues of the Conformal Laplace operator. This invariant vanishes if and only if the manifold has a metric of positive scalar curvature. We show that the invariant does not increase under surgery of codimension at least three and we give lower and upper bounds in terms of the alpha-genus.
Clones of n-ary algebras
(2003)