Description
This volume contains the proceedings of the international conference “Ordered Algebraic Structures and Related Topics”, held from October 12–16, 2015, at CIRM, Luminy, Marseilles, France.
Papers contained in this volume cover topics in real analytic geometry, real algebra, and real algebraic geometry including complexity issues, model theory of various algebraic and differential structures, Witt equivalence of fields, and the moment problem.
Chapter
Program of the conference
Some results on global real analytic geometry
1. Emergence of real analytic spaces
2. Inequalities and the global approach
3. Amenable 𝐶-semianalytic sets and irreducible components
Dimension in the realm of transseries
1. Differential-algebraic dimension
2. Dimension and codimension
4. Dimension 0 = discrete
5. Parametrizability by constants
6. Dimension 0 = co-analyzable relative to the constant field
Stability index of algebras with involution
4. Stability index of algebras with involution
Efficient algorithms for computing the Euler-Poincaré characteristic of symmetric semi-algebraic sets
2. Mathematical preliminaries
3. Equivariant deformation
4. Algorithms and the proofs of the main theorems
1. Gram matrices and sums of squares
2. Connections to toric geometry
3. Ranks on Gram spectrahedra
4. Examples: Binary forms and ternary quartics
5. Hermitian Gram spectrahedra
6. Sums of squares on products of simplices
Constructions in the category of real semigroups
2. Real semigroups of continuous functions
5. The space of RS-characters of products of real semigroups
6. The Functor from Preordered Rings to Real Semigroups
Recent progress on definability of Henselian valuations
1. Definability of a given henselian valuation
2. Definable henselian valuations on a given henselian field
3. Quantifier complexity and questions of uniformity
Polynomial, regular and Nash images of Euclidean spaces
1. First examples and obstructions
2. One dimensional polynomial and regular images of \Rⁿ
3. Examples and obstructions for dimension two
4. Obstructions for the boundaries of polynomial images
5. Piecewise linear semialgebraic sets as polynomial and regular images
Witt equivalence of fields: A survey with a special emphasis on applications of hyperfields
5. Henselian valued fields
7. Behaviour of orderings and valuations under Witt equivalence
10. Function fields over local and global fields
Infinite dimensional moment problem: open questions and applications
2. The moment problem on lmc topological \RR-algebras
3. The moment problem on symmetric algebras of lc real spaces
A new proof for the existence of degree bounds for Putinar’s Positivstellensatz
1. Introduction, definitions and historical outline of the problem
2. The purpose of the main theorem and its requirements
Coincidence point theorems for ball spaces and their applications
2. Proofs of the main theorems
3. Applications to ultrametric spaces
4. An application to complete metric spaces
5. An application to ordered abelian groups and fields
Valuation theory of exponential Hardy fields II: Principal parts of germs in the Hardy field of o-minimal exponential expansions of the reals
3. A general structure theorem for 𝐿𝐸_{\cal𝐹}(𝑥)
4. An intrinsic version of “truncation at 0”
Théories géométriques pour l’algèbre des nombres réels
2. Théories dynamiques pour les corps ordonnés
3. Corps ordonnés réels clos non discrets
Surreal numbers with derivation, Hardy fields and transseries: a survey
3. From Hardy fields to transseries and 𝐻-fields
Polynomials nonnegative on the cylinder
Positive semifields and their ideals
2. Definition of semifields, and examples
4. Ideals and factor semifields
5. The ideal spectrum of a semifield
6. Cancellation modulo ideals and the cancellation radical
8. Ideals under semifield extensions
On the strength of some topological lattices
2. The weak monadic structure of a first order structure
3. Finite unions of closed intervals
4. Defining closed and bounded intervals
5. Linear spaces and convex sets
6. Lattices of closed definable sets in the ordered context
7. Zariski closed sets and p-adic sets
On the local geometry of definably stratified sets
3. Normal pseudo-flatness in the non-polynomially bounded case