2期

最新文章

• Positive definite n-regular quadratic forms AI翻译
  作者：Oh, Byeong-Kweon
  作者单位：Sejong University
  摘要：A positive definite integral quadratic form f is called n-regular if f represents every quadratic form of rank n that is represented by the genus of f. In this paper, we show that for any integer n greater than or equal to 27, every n-regular (even) form f is (even) n-universal, that is, f represents all (even, respectively) positive definite integral quadratic forms of rank n. As an application, we show that the minimal rank of n-regular forms has an exponential lower bound for n as it increa...
• Cocycle and orbit equivalence superrigidity for malleable actions of w-rigid groups AI翻译
  作者：Popa, Sorin
  作者单位：University of California System; University of California Los Angeles
  摘要：We prove that if a countable discrete group Gamma is w- rigid, i. e. it contains an infinite normal subgroup H with the relative property (T) (e.g. Gamma = SL(2, Z) x Z(2), or Gamma = H x H' with H an infinite Kazhdan group and H' arbitrary), and V is a closed subgroup of the group of unitaries of a finite separable von Neumann algebra (e.g. V countable discrete, or separable compact), then any V- valued measurable cocycle for a measure preserving action Gamma curved right arrow X of Gamma on ...
• Symmetric groups and expander graphs AI翻译
  作者：Kassabov, Martin
  作者单位：Cornell University
  摘要：We construct explicit generating sets S-n and S-n of the alternating and the symmetric groups, which turn the Cayley graphs C(Alt(n), S-n) and C(Sym( n), S-n) into a family of bounded degree expanders for all n.
• Complex zeros of real ergodic eigenfunctions AI翻译
  作者：Zelditch, Steve
  作者单位：Johns Hopkins University
  摘要：We determine the limit distribution (as lambda -> infinity) of complex zeros for holomorphic continuations p(lambda)(C) to Grauert tubes of real eigenfunctions of the Laplacian on a real analytic compact Riemannian manifold (M, g) with ergodic geodesic flow. If {p(jk)} is an ergodic sequence of eigenfunctions, we prove the weak limit formula 1/lambda j [Z(pjk)(C)] -> i/pi partial derivative partial derivative vertical bar xi vertical bar(g), where [Z(pjk)(C)] is the current of integration over...
• Right-veering diffeomorphisms of compact surfaces with boundary AI翻译
  作者：Honda, Ko; Kazez, William H.; Matic, Gordana
  作者单位：University of Southern California; University System of Georgia; University of Georgia
  摘要：We initiate the study of the monoid of right-veering diffeomorphisms on a compact oriented surface with nonempty boundary. The monoid strictly contains the monoid of products of positive Dehn twists. We explain the relationship to tight contact structures and open book decompositions.
• Hida families and rational points on elliptic curves AI翻译
  作者：Bertolini, Massimo; Darmon, Henri
  作者单位：University of Milan; McGill University
• The Bogomolov conjecture for totally degenerate abelian varieties AI翻译
  作者：Gubler, Walter
  作者单位：Dortmund University of Technology
  摘要：We prove the Bogomolov conjecture for a totally degenerate abelian variety A over a function field. We adapt Zhang's proof of the number field case replacing the complex analytic tools by tropical analytic geometry. A key step is the tropical equidistribution theorem for A at the totally degenerate place v. As a corollary, we obtain finiteness of torsion points with coordinates in the maximal unramified algebraic extension over v.
• On the classification of simple inductive limit C*-algebras, II: The isomorphism theorem AI翻译
  作者：Elliott, George A.; Gong, Guihua; Li, Liangqing
  作者单位：University of Toronto; Hebei Normal University; University of Puerto Rico; University of Puerto Rico Rio Piedras
  摘要：In this article, it is proved that the invariant consisting of the scaled ordered K-group and the space of tracial states, together with the natural pairing between them, is a complete invariant for the class of unital simple C*-algebras which can be expressed as the inductive limit of a sequence A(1) -> A(2) -> ... -> A(n) -> ... with /A(n) = circle plus(tn)(i=1) Pn,iM[n,i](C(X-n,X-i))P-n,P-i, where X (n,i) is a compact metrizable space and P (n,i) is a projection in M-[n,M-i](C(X (n,i) )) fo...
• Finiteness properties of arithmetic groups over function fields AI翻译
  作者：Bux, Kai-Uwe; Wortman, Kevin
  作者单位：University of Virginia; Yale University
  摘要：We determine when an arithmetic subgroup of a reductive group defined over a global function field is of type FP infinity by comparing its largescale geometry to the large-scale geometry of lattices in real semisimple Lie groups.
• Fake projective planes AI翻译
  作者：Prasad, Gopal; Yeung, Sai-Kee
  作者单位：University of Michigan System; University of Michigan; Purdue University System; Purdue University