Results 1 - 10 of 6134
Results 1 - 10 of 6134. Search took: 0.029 seconds
|Sort by: date | relevance|
[en] Characteristic Lie rings for Toda and Volterra type (2 + 1)-dimensional lattices are defined. Some properties of these rings are studied. Infinite sequence of special kind subrings are introduced. It is proved that for known integrable lattices these subrings are of finite dimension. A classification algorithm based on this observation is suggested. (paper)
[en] Vector bundles on the projective line over a Dedekind domain A are studied. In the case where A is a principal ideal domain, a complete classification is obtained for rank 2 vector bundles with generic fiber O ⊕ O(1) and special fibers isomorphic either to O ⊕ O(1) or to O(−1) ⊕ O(2).
[en] We show that a new multiplicative genus, in the sense of Hirzebruch, can be obtained by generalizing a calculation due to Atiyah and Witten. We introduce this as the Γ-hat-genus, compute its value for some examples and highlight some of its interesting properties. We also indicate a connection with the study of multiple zeta values, which gives an algebraic interpretation for our proposed regularization procedure
[en] The Hochschild cohomology groups are computed for algebras of semidihedral type, which are contained in the family SD(2ℬ)2(k, t, c) (from the famous K. Erdmann’s classification) in the case where k = 1. In the calculation, the beforehand construction of the minimal bimodule resolution for algebras from the subfamily under discussion is used.
[en] The (generalized) Rainich conditions are algebraic conditions which are polynomial in the (mixed-component) stress–energy tensor. As such they are logically distinct from the usual classical energy conditions (NEC, WEC, SEC, DEC), and logically distinct from the usual Hawking–Ellis (Segré–Plebański) classification of stress–energy tensors (type I, type II, type III, type IV). There will of course be significant inter-connections between these classification schemes, which we explore in the current article. Overall, we shall argue that it is best to view the (generalized) Rainich conditions as a refinement of the classical energy conditions and the usual Hawking–Ellis classification. (paper)
[en] We investigate various types of squeezing in a collective su() system consisting of spin-J particles (). We show that squeezing in the collective su() system can be classified into unitary equivalence classes, each of which is characterized by a set of squeezed and anti-squeezed observables forming an su(2) subalgebra in the su() algebra. The dimensionality of the unitary equivalence class is found to be fundamentally related to its squeezing limit. We also demonstrate the classification of squeezing among the spin and multipolar observables in a collective su(4) system. (paper)
[en] We suggest a new concept of t-stability in a triangulated category. It generalizes the stability data introduced by Bridgeland. We study some links between t-stabilities and t-structures and obtain a complete classification of t-stabilities and bounded t-structures on the derived categories of coherent sheaves on the projective line and on an elliptic curve