Cyclic actions on - and -bundles over
Józef H. Przytycki (1982)
Colloquium Mathematicae
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Józef H. Przytycki (1982)
Colloquium Mathematicae
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T. E. Barros (2001)
Bulletin de la Société Mathématique de France
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In [R] explicit representatives for -principal bundles over are constructed, based on these constructions explicit free -actions on the total spaces are described, with quotients exotic -spheres. To describe these actions a classification formula for the bundles is used. This formula is not correct. In Theorem 1 below, we correct the classification formula and in Theorem 2 we exhibit the correct indices of the exotic -spheres that occur as quotients of the free -actions described...
Sergei Yu. Pilyugin, Sergei B. Tikhomirov (2003)
Fundamenta Mathematicae
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We study shadowing properties of continuous actions of the groups and . Necessary and sufficient conditions are given under which a linear action of on has a Lipschitz shadowing property.
John Kalliongis, Ryo Ohashi (2017)
Commentationes Mathematicae Universitatis Carolinae
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We describe the finite group actions, up to equivalence, which can act on the orbifold , and their quotient types. This is then used to consider actions on prism manifolds which preserve a longitudinal fibering, but do not leave any Heegaard Klein bottle invariant. If is such an action, we show that and fibers over a certain collection of 2-orbifolds with positive Euler characteristic which are covered by . For the standard actions, we compute the fundamental group of and...
Adrian Ioana (2009)
Annales scientifiques de l'École Normale Supérieure
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For any , we construct a concrete 1-parameter family of non-orbit equivalent actions of the free group . These actions arise as diagonal products between a generalized Bernoulli action and the action , where is seen as a subgroup of .
Roberto Muñoz, Luis E. Solá Conde, Gianluca Occhetta (2014)
Annales de l’institut Fourier
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In this paper we classify rank two Fano bundles on Fano manifolds satisfying . The classification is obtained via the computation of the nef and pseudoeffective cones of the projectivization , that allows us to obtain the cohomological invariants of and . As a by-product we discuss Fano bundles associated to congruences of lines, showing that their varieties of minimal rational tangents may have several linear components.
Stefaan Vaes (2008)
Annales scientifiques de l'École Normale Supérieure
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We study II factors and associated with good generalized Bernoulli actions of groups having an infinite almost normal subgroup with the relative property (T). We prove the following rigidity result : every finite index --bimodule (in particular, every isomorphism between and ) is described by a commensurability of the groups involved and a commensurability of their actions. The fusion algebra of finite index --bimodules is identified with an extended Hecke fusion algebra,...
Bruno P. Zimmermann (2014)
Fundamenta Mathematicae
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Let denote the closed 3-manifold obtained as the connected sum of g copies of S² × S¹, with free fundamental group of rank g. We prove that, for a finite group G acting on which induces a faithful action on the fundamental group, there is an upper bound for the order of G which is quadratic in g, but there does not exist a linear bound in g. This implies then a Jordan-type bound for arbitrary finite group actions on which is quadratic in g. For the proofs we develop a calculus...
Lutz Hille, Markus Perling (2014)
Annales de l’institut Fourier
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Let be any rational surface. We construct a tilting bundle on . Moreover, we can choose in such way that its endomorphism algebra is quasi-hereditary. In particular, the bounded derived category of coherent sheaves on is equivalent to the bounded derived category of finitely generated modules over a finite dimensional quasi-hereditary algebra . The construction starts with a full exceptional sequence of line bundles on and uses universal extensions. If is any smooth projective...
J. Kurek, W. M. Mikulski (2010)
Annales Polonici Mathematici
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Let m and r be natural numbers and let be the rth order frame bundle functor. Let and be natural bundles, where . We describe all -natural operators A transforming sections σ of and classical linear connections ∇ on M into sections A(σ,∇) of . We apply this general classification result to many important natural bundles F and G and obtain many particular classifications.
Burt Totaro (2013)
Journal of the European Mathematical Society
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Define a line bundle on a projective variety to be -ample, for a natural number , if tensoring with high powers of kills coherent sheaf cohomology above dimension . Thus 0-ampleness is the usual notion of ampleness. We show that -ampleness of a line bundle on a projective variety in characteristic zero is equivalent to the vanishing of an explicit finite list of cohomology groups. It follows that -ampleness is a Zariski open condition, which is not clear from the definition. ...
Giovanni Felder, A. Veselov (2005)
Journal of the European Mathematical Society
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We consider both standard and twisted actions of a (real) Coxeter group on the complement to the complexified reflection hyperplanes by combining the reflections with complex conjugation. We introduce a natural geometric class of special involutions in and give explicit formulae which describe both actions on the total cohomology in terms of these involutions. As a corollary we prove that the corresponding twisted representation is regular only for the symmetric group , the...
Ionut Chifan, Thomas Sinclair (2013)
Annales scientifiques de l'École Normale Supérieure
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Ozawa showed in [21] that for any i.c.c. hyperbolic group, the associated group factor is solid. Developing a new approach that combines some methods of Peterson [29], Ozawa and Popa [27, 28], and Ozawa [25], we strengthen this result by showing that is strongly solid. Using our methods in cooperation with a cocycle superrigidity result of Ioana [12], we show that profinite actions of lattices in , , are virtually -superrigid.
(2025)
Archivum Mathematicum
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Philippe Bonnet (2003)
Bulletin de la Société Mathématique de France
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Let be a polynomial dominating map from to . We study the quotient of polynomial 1-forms that are exact along the generic fibres of , by 1-forms of type , where are polynomials. We prove that is always a torsion -module. Then we determine under which conditions on we have . As an application, we study the behaviour of a class of algebraic -actions on , and determine in particular when these actions are trivial.
David Ben-Zvi, Thomas Nevins (2011)
Journal of the European Mathematical Society
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We study the geometry of -bundles—locally projective -modules—on algebraic curves, and apply them to the study of integrable hierarchies, specifically the multicomponent Kadomtsev–Petviashvili (KP) and spin Calogero–Moser (CM) hierarchies. We show that KP hierarchies have a geometric description as flows on moduli spaces of -bundles; in particular, we prove that the local structure of -bundles is captured by the full Sato Grassmannian. The rational, trigonometric, and elliptic solutions...
Pedro L. Q. Pergher, Rogério de Oliveira (2005)
Fundamenta Mathematicae
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Let Fⁿ be a connected, smooth and closed n-dimensional manifold satisfying the following property: if is any smooth and closed m-dimensional manifold with m > n and is a smooth involution whose fixed point set is Fⁿ, then m = 2n. We describe the equivariant cobordism classification of smooth actions of the group on closed smooth m-dimensional manifolds for which the fixed point set of the action is a submanifold Fⁿ with the above property. This generalizes a result of F....
Jan Kurek, Włodzimierz Mikulski (2014)
Annales Universitatis Mariae Curie-Sklodowska, sectio A – Mathematica
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If is a Riemannian manifold, we have the well-known base preserving vector bundle isomorphism given by between the tangent and the cotangent bundles of . In the present note, we generalize this isomorphism to the one between the -th order vector tangent and the -th order cotangent bundles of . Next, we describe all base preserving vector bundle maps depending on a Riemannian metric in terms of natural (in ) tensor fields on .
Parameswaran Sankaran, Ajay Singh Thakur (2013)
Annales de l’institut Fourier
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Let be a holomorphic line bundle over a compact complex manifold for . Let denote the associated principal circle-bundle with respect to some hermitian inner product on . We construct complex structures on which we refer to as
Piotr Oprocha (2008)
Colloquium Mathematicae
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We show that the class of expansive actions with P.O.T.P. is wider than the class of actions topologically hyperbolic in some direction . Our main tool is an extension of a result by Walters to the multi-dimensional symbolic dynamics case.
Fabrizio Catanese, Fabio Tonoli (2007)
Journal of the European Mathematical Society
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We determine the possible even sets of nodes on sextic surfaces in , showing in particular that their cardinalities are exactly the numbers in the set . We also show that all the possible cases admit an explicit description. The methods that we use are an interplay of coding theory and projective geometry on one hand, and of homological and computer algebra on the other. We give a detailed geometric construction for the new case of an even set of 56 nodes, but the ultimate verification...
Jarosław Kwapisz (2010)
Fundamenta Mathematicae
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For a continuous map f preserving orbits of an aperiodic -action on a compact space, its displacement function assigns to x the “time” it takes to move x to f(x). We show that this function is continuous if the action is minimal. In particular, f is homotopic to the identity along the orbits of the action.
Carlos Rito (2007)
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze
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This paper classifies surfaces of general type with having an involution such that has non-negative Kodaira dimension and that the bicanonical map of factors through the double cover induced by It is shown that is regular and either: a) the Albanese fibration of is of genus 2 or b) has no genus 2 fibration and is birational to a surface. For case a) a list of possibilities and examples are given. An example for case b) with is also constructed.