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• The Monge-Ampere operator and geodesics in the space of Kahler potentials AI翻译
  作者：Phong, D. H.; Sturm, Jacob
  作者单位：Columbia University; Rutgers University System; Rutgers University New Brunswick; Rutgers University Newark
• Toda lattice, cohomology of compact Lie groups and finite Chevalley groups AI翻译
  作者：Casian, Luis; Kodama, Yuji
  作者单位：University System of Ohio; Ohio State University
• Universal lattices and property tau AI翻译
  作者：Kassabov, Martin; Nikolov, Nikolay
  作者单位：Cornell University; University of Oxford
  摘要：We prove that the universal lattices - the groups G = SLd(R) where R = Z[x(1),..., x(k)], have property tau for d >= 3. This provides the first example of linear groups with t which do not come from arithmetic groups. We also give a lower bound for the tau-constant with respect to the natural generating set of G. Our methods are based on bounded elementary generation of the finite congruence images of G, a generalization of a result by Dennis and Stein on K-2 of some finite commutative rings a...
• The Weyl groupoid of a Nichols algebra of diagonal type AI翻译
  作者：Heckenberger, I
  作者单位：Leipzig University
  摘要：The theory of Nichols algebras of diagonal type is known to be closely related to that of semi-simple Lie algebras. In this paper the connection between both theories is made closer. For any Nichols algebra of diagonal type invertible transformations are introduced, which remind one of the action of the Weyl group on the root system associated to a semi-simple Lie algebra. They give rise to the definition of a groupoid. As an application an alternative proof of classification results of Rosso,...
• Virasoro constraints for target curves AI翻译
  作者：Okounkov, A; Pandharipande, R
  作者单位：Princeton University
  摘要：We prove generalized Virasoro constraints for the relative Gromov-Witten theories of all nonsingular target curves. Descendents of the even cohomology classes are studied first by localization, degeneration, and completed cycle methods. Descendents of the odd cohomology are then controlled by monodromy and geometric vanishing relations. As an outcome of our results, the relative theories of target curves are completely and explicitly determined.We prove generalized Virasoro constraints for the...
• Kg is not finitely generated AI翻译
  作者：Biss, D; Farb, B
  作者单位：University of Chicago
• The obstruction to excision in K-theory and in cyclic homology AI翻译
  作者：Cortiñas, G
  摘要：Let f : A -> B be a ring homomorphism of not necessarily unital rings and I Delta A an ideal which is mapped by f isomorphically to an ideal of B. The obstruction to excision in K-theory is the failure of the map between relative K-groups K-*(A : I). K-*(B:f(I)) to be an isomorphism; it is measured by the birelative groups K-*(A,B:I). Similarly the groups HN*(A,B:I) measure the obstruction to excision in negative cyclic homology. We show that the rational Jones-Goodwillie Chern character induc...
• Local Andre-Oort conjecture for the universal abelian variety AI翻译
  作者：Scanlon, T
  作者单位：University of California System; University of California Berkeley
  摘要：We prove a p-adic version of the Andre-Oort conjecture for subvarieties of the universal abelian varieties. Let g and n be integers with n >= 3 and p a prime number not dividing n. Let R be a finite extension of W[F-p(alg)], the ring of Witt vectors of the algebraic closure of the field of p elements. The moduli space A = A(g,1,n) of g-dimensional principally polarized abelian varieties with full level n-structure as well as the universal abelian variety p : X --> A over A may be defined over ...