Results 51 to 60 of about 104,157 (229)
On the automorphism group of a matroid
Discrete Mathematics, 1972 AbstractWe show that for any group H (finite or infinite) there exists an independence structure with automorphism group isomorphic to H. The proof is by construction and shows that for any H there is a geometric lattice with automorphism group isomorphic to H.
Harary, Frank +2 more
openaire +3 more sources
On Endomorphism Universality of Sparse Graph Classes
Journal of Graph Theory, EarlyView.ABSTRACT We show that every commutative idempotent monoid (a.k.a. lattice) is the endomorphism monoid of a subcubic graph. This solves a problem of Babai and Pultr and the degree bound is best‐possible. On the other hand, we show that no class excluding a minor can have all commutative idempotent monoids among its endomorphism monoids. As a by‐product,
Kolja Knauer, Gil Puig i Surroca
wiley +1 more source
General infinitesimal variations of the Hodge structure of ample curves in surfaces
Mathematische Nachrichten, EarlyView.Abstract Given a smooth projective complex curve inside a smooth projective surface, one can ask how its Hodge structure varies when the curve moves inside the surface. In this paper, we develop a general theory to study the infinitesimal version of this question in the case of ample curves.
Víctor González‐Alonso, Sara Torelli
wiley +1 more source
The affine automorphism group of A^3 is not a maximal subgroup of the tame automorphism group
, 2014 We construct explicitly a family of proper subgroups of the tame automorphism group of affine three-space (in any characteristic) which are generated by the affine subgroup and a non-affine tame automorphism. One important corollary is the titular result
Edo, Eric, Lewis, Drew
core +2 more sources
Spectra of subrings of cohomology generated by characteristic classes for fusion systems
Bulletin of the London Mathematical Society, EarlyView.Abstract If F$\mathcal {F}$ is a saturated fusion system on a finite p$p$‐group S$S$, we define the Chern subring Ch(F)${\operatorname{Ch}}(\mathcal {F})$ of F$\mathcal {F}$ to be the subring of H∗(S;Fp)$H^*(S;{\mathbb {F}}_p)$ generated by Chern classes of F$\mathcal {F}$‐stable representations of S$S$. We show that Ch(F)${\operatorname{Ch}}(\mathcal {
Ian J. Leary, Jason Semeraro
wiley +1 more source
ON EQUALITY OF ABSOLUTE CENTRAL AND CLASS PRESERVING AUTOMORPHISMS OF FINITE p-GROUPS [PDF]
Journal of Algebraic Systems, 2019 Let $G$ be a finite non-abelian $p$-group and $L(G)$ denotes the absolute center of $G$. Also, let $Aut^{L}(G)$ and $Aut_c(G)$ denote the group of all absolute central and the class preserving automorphisms of $G$, respectively.
Rasoul Soleimani
doaj +1 more source
A Group of Automorphisms of the Homotopy Groups [PDF]
Nagoya Mathematical Journal, 1951 It is well known that the fundamental group π1(X) of an arcwise connected topological space X operates on the n-th homotopy group πn(X) of X as a group of automorphisms. In this paper I intend to construct geometrically a group 𝒰(X) of automorphisms of πn(X), for every integer n ≥ 1, which includes a normal subgroup isomorphic to π1(X) so that the ...
openaire +2 more sources
Presentation of kernels of rational characters of right‐angled Artin groups
Bulletin of the London Mathematical Society, EarlyView.Abstract In this note, we characterise when the kernel of a rational character of a right‐angled Artin group, also known as generalised Bestiva–Brady group, is finitely generated and finitely presented. In these cases, we exhibit a finite generating set and a presentation.
Montserrat Casals‐Ruiz +2 more
wiley +1 more source
On Groups in Which Many Automorphisms Are Cyclic
Mathematics, 2022 Let G be a group. An automorphism α of G is said to be a cyclic automorphism if the subgroup ⟨x,xα⟩ is cyclic for every element x of G. In [F. de Giovanni, M.L. Newell, A. Russo: On a class of normal endomorphisms of groups, J.
Mattia Brescia, Alessio Russo
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Graphical models for topological groups: A case study on countable Stone spaces
Bulletin of the London Mathematical Society, EarlyView.Abstract By analogy with the Cayley graph of a group with respect to a finite generating set or the Cayley–Abels graph of a totally disconnected, locally compact group, we detail countable connected graphs associated to Polish groups that we term Cayley–Abels–Rosendal graphs.
Beth Branman +3 more
wiley +1 more source