Displaying similar documents to “The Strong Anick Conjecture is true”

Automorphisms of ( λ ) / κ

Paul Larson, Paul McKenney (2016)

Fundamenta Mathematicae

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We study conditions on automorphisms of Boolean algebras of the form ( λ ) / κ (where λ is an uncountable cardinal and κ is the ideal of sets of cardinality less than κ ) which allow one to conclude that a given automorphism is trivial. We show (among other things) that every automorphism of ( 2 κ ) / κ which is trivial on all sets of cardinality κ⁺ is trivial, and that M A implies both that every automorphism of (ℝ)/Fin is trivial on a cocountable set and that every automorphism of (ℝ)/Ctble is trivial. ...

On Automorphisms of the Affine Cremona Group

Hanspeter Kraft, Immanuel Stampfli (2013)

Annales de l’institut Fourier

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We show that every automorphism of the group 𝒢 n : = A u t ( 𝔸 n ) of polynomial automorphisms of complex affine n -space 𝔸 n = n is inner up to field automorphisms when restricted to the subgroup T 𝒢 n of tame automorphisms. This generalizes a result of Julie Deserti who proved this in dimension n = 2 where all automorphisms are tame: T 𝒢 2 = 𝒢 2 . The methods are different, based on arguments from algebraic group actions.

Discretized C * -Algebras

Carla Farsi, Neil Watling (2006)

Bollettino dell'Unione Matematica Italiana

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We define discretized canonical commutation relations associated to finite order automorphisms of discrete abelian groups. This generalizes the situation for rotation algebras and their finite order automorphisms. We also consider the almost Schrödinger operator associated to the given commutation relations.

Division algebras that generalize Dickson semifields

Daniel Thompson (2020)

Communications in Mathematics

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We generalize Knuth’s construction of Case I semifields quadratic over a weak nucleus, also known as generalized Dickson semifields, by doubling of central simple algebras. We thus obtain division algebras of dimension 2 s 2 by doubling central division algebras of degree s . Results on isomorphisms and automorphisms of these algebras are obtained in certain cases.

Coleman automorphisms of finite groups with a self-centralizing normal subgroup

Jinke Hai (2020)

Czechoslovak Mathematical Journal

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Let G be a finite group with a normal subgroup N such that C G ( N ) N . It is shown that under some conditions, Coleman automorphisms of G are inner. Interest in such automorphisms arose from the study of the normalizer problem for integral group rings.

The Wells map for abelian extensions of 3-Lie algebras

Youjun Tan, Senrong Xu (2019)

Czechoslovak Mathematical Journal

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The Wells map relates automorphisms with cohomology in the setting of extensions of groups and Lie algebras. We construct the Wells map for some abelian extensions 0 A L π B 0 of 3-Lie algebras to obtain obstruction classes in H 1 ( B , A ) for a pair of automorphisms in Aut ( A ) × Aut ( B ) to be inducible from an automorphism of L . Application to free nilpotent 3-Lie algebras is discussed.

Non-standard automorphisms of branched coverings of a disk and a sphere

Bronisław Wajnryb, Agnieszka Wiśniowska-Wajnryb (2012)

Fundamenta Mathematicae

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Let Y be a closed 2-dimensional disk or a 2-sphere. We consider a simple, d-sheeted branched covering π: X → Y. We fix a base point A₀ in Y (A₀ ∈ ∂Y if Y is a disk). We consider the homeomorphisms h of Y which fix ∂Y pointwise and lift to homeomorphisms ϕ of X-the automorphisms of π. We prove that if Y is a sphere then every such ϕ is isotopic by a fiber-preserving isotopy to an automorphism which fixes the fiber π - 1 ( A ) pointwise. If Y is a disk, we describe explicitly a small set of automorphisms...

Infinitesimal CR automorphisms for a class of polynomial models

Martin Kolář, Francine Meylan (2017)

Archivum Mathematicum

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In this paper we study infinitesimal CR automorphisms of Levi degenerate hypersurfaces. We illustrate the recent general results of [18], [17], [15], on a class of concrete examples, polynomial models in 3 of the form w = ( P ( z ) Q ( z ) ¯ ) , where P and Q are weighted homogeneous holomorphic polynomials in z = ( z 1 , z 2 ) . We classify such models according to their Lie algebra of infinitesimal CR automorphisms. We also give the first example of a non monomial model which admits a nonlinear rigid automorphism. ...

Automorphisms of central extensions of type I von Neumann algebras

Sergio Albeverio, Shavkat Ayupov, Karimbergen Kudaybergenov, Rauaj Djumamuratov (2011)

Studia Mathematica

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Given a von Neumann algebra M we consider its central extension E(M). For type I von Neumann algebras, E(M) coincides with the algebra LS(M) of all locally measurable operators affiliated with M. In this case we show that an arbitrary automorphism T of E(M) can be decomposed as T = T a T ϕ , where T a ( x ) = a x a - 1 is an inner automorphism implemented by an element a ∈ E(M), and T ϕ is a special automorphism generated by an automorphism ϕ of the center of E(M). In particular if M is of type I then every band preserving...

The group of automorphisms of L is algebraically reflexive

Félix Cabello Sánchez (2004)

Studia Mathematica

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We study the reflexivity of the automorphism (and the isometry) group of the Banach algebras L ( μ ) for various measures μ. We prove that if μ is a non-atomic σ-finite measure, then the automorphism group (or the isometry group) of L ( μ ) is [algebraically] reflexive if and only if L ( μ ) is *-isomorphic to L [ 0 , 1 ] . For purely atomic measures, we show that the group of automorphisms (or isometries) of ( Γ ) is reflexive if and only if Γ has non-measurable cardinal. So, for most “practical” purposes, the automorphism...

Artinian automorphisms of infinite groups

Antonella Leone (2006)

Bollettino dell'Unione Matematica Italiana

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An automorphism a of a group G is called an artinian automorphism if for every strictly descending chain H 1 > H 2 > > H n > of subgroups of G there exists a positive integer m such that ( H n ) a = H n for every n m . In this paper we show that in many cases the group of all artinian automorphisms of G coincides with the group of all power automorphisms of G .

Combinatorial mapping-torus, branched surfaces and free group automorphisms

François Gautero (2007)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

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We give a characterization of the geometric automorphisms in a certain class of (not necessarily irreducible) free group automorphisms. When the automorphism is geometric, then it is induced by a pseudo-Anosov homeomorphism without interior singularities. An outer free group automorphism is given by a 1 -cocycle of a 2 -complex (a standard dynamical branched surface, see [7] and [9]) the fundamental group of which is the mapping-torus group of the automorphism. A combinatorial construction...

Automorphisms of Spacetime Manifold with Torsion

Vladimir Ivanovich Pan’Zhenskii, Olga Petrovna Surina (2016)

Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica

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In this paper we prove that the maximum dimension of the Lie group of automorphisms of the Riemann–Cartan 4-dimensional manifold does not exceed 8, and if the Cartan connection is skew-symmetric or semisymmetric, the maximum dimension is equal to 7. In addition, in the case of the Riemann–Cartan n -dimensional manifolds with semisymmetric connection the maximum dimension of the Lie group of automorphisms is equal to n ( n - 1 ) / 2 + 1 for any n > 2 .

Automorphisms and derivations of a Fréchet algebra of locally integrable functions

F. Ghahramani, J. McClure (1992)

Studia Mathematica

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We find representations for the automorphisms, derivations and multipliers of the Fréchet algebra L ¹ l o c of locally integrable functions on the half-line + . We show, among other things, that every automorphism θ of L ¹ l o c is of the form θ = φ a e λ X e D , where D is a derivation, X is the operator of multiplication by coordinate, λ is a complex number, a > 0, and φ a is the dilation operator ( φ a f ) ( x ) = a f ( a x ) ( f L ¹ l o c , x + ). It is also shown that the automorphism group is a topological group with the topology of uniform convergence...

Automorphisms of the algebra of operators in p preserving conditioning

Ryszard Jajte (2010)

Colloquium Mathematicae

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Let α be an isometric automorphism of the algebra p of bounded linear operators in p [ 0 , 1 ] (p ≥ 1). Then α transforms conditional expectations into conditional expectations if and only if α is induced by a measure preserving isomorphism of [0, 1].

The groups of automorphisms of the Witt W n and Virasoro Lie algebras

Vladimir V. Bavula (2016)

Czechoslovak Mathematical Journal

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Let L n = K [ x 1 ± 1 , ... , x n ± 1 ] be a Laurent polynomial algebra over a field K of characteristic zero, W n : = Der K ( L n ) the Lie algebra of K -derivations of the algebra L n , the so-called Witt Lie algebra, and let Vir be the Virasoro Lie algebra which is a 1 -dimensional central extension of the Witt Lie algebra. The Lie algebras W n and Vir are infinite dimensional Lie algebras. We prove that the following isomorphisms of the groups of Lie algebra automorphisms hold: Aut Lie ( Vir ) Aut Lie ( W 1 ) { ± 1 } K * , and give a short proof that Aut Lie ( W n ) Aut K - alg ( L n ) GL n ( ) K * n .

The Banach-Lie Group of Lie Automorphisms of an H * -Algebra

Antonio J. Calderón Martín, Candido Martín González (2007)

Bollettino dell'Unione Matematica Italiana

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We study the Banach-Lie group Aut ( A - ) of Lie automorphisms of a complex associative H * -algebra. Also some consequences about its Lie algebra, the algebra of Lie derivations of A , are obtained. For a topologically simple A , in the infinite-dimensional case we have Aut ( A - ) 0 = Aut ( A ) implying Der ( A ) = Der ( A - ) . In the finite dimensional case Aut ( A - ) 0 is a direct product of Aut ( A ) and a certain subgroup of Lie derivations δ from A to its center, annihilating commutators.

On automorphisms of the Banach space / c

Piotr Koszmider, Cristóbal Rodríguez-Porras (2016)

Fundamenta Mathematicae

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We investigate Banach space automorphisms T : / c / c focusing on the possibility of representing their fragments of the form T B , A : ( A ) / c ( A ) ( B ) / c ( B ) for A,B ⊆ ℕ infinite by means of linear operators from ( A ) into ( B ) , infinite A×B-matrices, continuous maps from B* = βB∖B into A*, or bijections from B to A. This leads to the analysis of general bounded linear operators on / c . We present many examples, introduce and investigate several classes of operators, for some of them we obtain satisfactory representations and for...

On automorphisms fixing subnormal subgroups of soluble groups

Silvana Franciosi, Francesco de Giovanni (1988)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

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The group A u t s n G of all automorphisms leaving invariant every subnormal subgroup of the group G is studied. In particular it is proved that A u t s n G is metabelian if G is soluble, and that A u t s n G is either finite or abelian if G is polycyclic.