On an existence theorem of Wagner manifolds
نویسندگان
چکیده
منابع مشابه
On Berwald and Wagner Manifolds
Berwald and Wagner manifolds are two important classes of spaces in Finsler geometry. They are closely related to each other via the conformal change of the metric. After discussing the basic definitions and the elements of the theory we present general methods to construct examples of them.
متن کاملOn the Livingstone-Wagner Theorem
Let G be a permutation group on the set Ω and let S be a collection of subsets of Ω, all of size ≥ m for some integer m . For s ≤ m let ns(G, S) be the number of G-orbits on the subsets of Ω which have a representative y ⊆ x with |y| = s and y ⊆ x for some x ∈ S . We prove that if s < t with s + t ≤ m then ns(G, S) ≤ nt(G, S) . A special case of this theorem is the Livingstone-Wagner Theorem wh...
متن کاملAn Existence Theorem for Stationary Discs in Almost Complex Manifolds
An existence theorem for stationary discs of strongly pseudo-convex domains in almost complex manifolds is proved. More precisely, it is shown that, for all points of a suitable neighborhood of the boundary and for any vector belonging to certain open subsets of the tangent spaces, there exists a unique stationary disc passing through that point and tangent to the given vector. Introduction Ana...
متن کاملThe Mermin-Wagner Theorem
LetA be a C∗ algebra such as the algebra of quasi-local observables of a quantum spin system on Z, and suppose {αt}t∈R is a strongly continuous one-parameter group of automorphisms of A, which we will refer to as the dynamics of the system. The examples we have in mind are the dynamics of a quantum spin system generated by a not-too-long-range interaction Φ, e.g., one that satsifies, for some λ...
متن کاملVariations on the Dembowski-Wagner theorem
Let D be a symmetric design admitting a null polarity such that either all singular lines, or all nonsingular lines, have size (v − λ)/(k − λ); assume that this number is greater than λ in the case of singular lines. Then D is either a projective space or an orthogonal symmetric design. © 2003 Elsevier Ltd. All rights reserved. The Dembowski–Wagner Theorem [3] characterizes projective spaces as...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Indagationes Mathematicae
سال: 2006
ISSN: 0019-3577
DOI: 10.1016/s0019-3577(06)80011-x