2017

最新文章

• Non-Hamiltonian actions with isolated fixed points AI翻译
  作者：Tolman, Susan
  作者单位：University of Illinois System; University of Illinois Urbana-Champaign
  摘要：We construct a non-Hamiltonian symplectic circle action on a closed, connected, six-dimensional symplectic manifold with exactly 32 fixed points.
• C*-simplicity and the amenable radical AI翻译
  作者：Le Boudec, Adrien
  作者单位：Universite Paris Saclay; Universite Catholique Louvain
  摘要：A countable group is -simple if its reduced -algebra is simple. It is well-known that -simplicity implies that the amenable radical of the group must be trivial. We show that the converse does not hold by constructing explicit counter-examples. We additionally prove that every countable group embeds into a countable group with trivial amenable radical and that is not C*-simple.
• Degree of -Alexander torsion for 3-manifolds AI翻译
  作者：Liu, Yi
  摘要：For an irreducible orientable compact 3-manifold N with empty or incompressible toral boundary, the full -Alexander torsion associated to any real first cohomology class of N is represented by a function of a positive real variable t. The paper shows that is continuous, everywhere positive, and asymptotically monomial in both ends. Moreover, the degree of equals the Thurston norm of . The result confirms a conjecture of J. Dubois, S. Friedl, and W. Luck and addresses a question of W. Li and W....
• The Jacobian module, the Milnor fiber, and the D-module generated by fs AI翻译
  作者：Walther, Uli
  作者单位：Purdue University System; Purdue University
  摘要：For a germ f on a complex manifold X, we introduce a complex derived from the Liouville form acting on logarithmic differential forms, and give an exactness criterion. We use this Liouville complex to connect properties of the D-module generated by to homological data of the Jacobian ideal; specifically we show that for a large class of germs the annihilator of is generated by derivations. Through local cohomology, we connect the cohomology of the Milnor fiber to the Jacobian module via logari...
• On the non-existence of right almost split maps AI翻译
  作者：Saroch, Jan
  作者单位：Charles University Prague
  摘要：We show that, over any ring, a module C is the codomain of a right almost split map, if and only if C is finitely presented with a local endomorphism ring. Thus we answer a 40-year-old question by Maurice Auslander.
• Sharp and rigid isoperimetric inequalities in metric-measure spaces with lower Ricci curvature bounds AI翻译
  作者：Cavalletti, Fabio; Mondino, Andrea
  作者单位：University of Pavia; Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Zurich
  摘要：We prove that if is a metric measure space with having (in a synthetic sense) Ricci curvature bounded from below by and dimension bounded above by , then the classic L,vy-Gromov isoperimetric inequality (together with the recent sharpening counterparts proved in the smooth setting by Milman for any , and upper diameter bounds) holds, i.e. the isoperimetric profile function of is bounded from below by the isoperimetric profile of the model space. Moreover, if equality is attained for some volum...
• The spectrum of the equivariant stable homotopy category of a finite group AI翻译
  作者：Balmer, Paul; Sanders, Beren
  作者单位：University of California System; University of California Los Angeles; University of Copenhagen
  摘要：We study the spectrum of prime ideals in the tensor-triangulated category of compact equivariant spectra over a finite group. We completely describe this spectrum as a set for all finite groups. We also make significant progress in determining its topology and obtain a complete answer for groups of square-free order. For general finite groups, we describe the topology up to an unresolved indeterminacy, which we reduce to the case of p-groups. We then translate the remaining unresolved question...
• Curvature estimates for immersed hypersurfaces in Riemannian manifolds AI翻译
  作者：Guan, Pengfei; Lu, Siyuan
  作者单位：McGill University
  摘要：We establish mean curvature estimate for immersed hypersurface with nonnegative extrinsic scalar curvature in Riemannian manifold (Nn+1,(g) over bar )through regularity study of a degenerate fully nonlinear curvature equation in general Riemannian manifold. The estimate has a direct consequence for the Weyl isometric embedding problem of (S-2, g) in 3-dimensional warped product space (N-3,(g) over bar) . We also discuss isometric embedding problem in spaces with horizon in general relativity, ...
• Prime number theorems and holonomies for hyperbolic rational maps AI翻译
  作者：Oh, Hee; Winter, Dale
  作者单位：Yale University; Korea Institute for Advanced Study (KIAS); Institute for Advanced Study - USA
  摘要：For a hyperbolic rational map f of degree at least two on the Riemann sphere, we obtain estimates for the number of primitive periodic orbits of f ordered by their multiplier, and establish equidistribution of the associated holonomies, both with power saving error terms.
• Convergence of formal CR mappings into strongly pseudoconvex Cauchy-Riemann manifolds AI翻译
  作者：Lamel, Bernhard; Mir, Nordine
  作者单位：University of Vienna; Qatar Foundation (QF); Texas A&M University Qatar
  摘要：It is shown that any formal holomorphic mapping sending a real-analytic generic submanifold M subset of C-N of finite type into a real-analytic strongly pseudoconvex CR submanifold M' subset of C-N' is necessarily convergent. As a consequence, we obtain a positive answer to the long-standing open question of whether formal holomorphic maps sending real-analytic strongly pseudoconvex hypersurfaces into each other are convergent.