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Related papers: Constructing Group-Invariant CR Mappings

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We construct group-invariant CR maps from the unit sphere in $\mathbb{C}^3$ and provide sharp bounds for the gap termination in this setting.

Complex Variables · Mathematics 2025-11-26 Mona Al Batrouni , Florian Bertrand

We analyze a canonical construction of group-invariant CR Mappings between hyperquadrics due to D'Angelo. Given source hyperquadric of $Q(1,1)$, we determine the signature of the target hyperquadric for all finite subgroups of $SU(1,1)$. We…

Complex Variables · Mathematics 2018-11-14 Dusty Grundmeier , Kemen Linsuain , Brendan Whitaker

We summarize some work on CR mappings invariant under a subgroup of U(n) and prove a result on the failure of rigidity.

Complex Variables · Mathematics 2009-06-02 John P. D'Angelo

Using elementary number theory, we prove several results about the complexity of CR mappings between spheres. It is known that CR mappings between spheres, invariant under finite groups, lead to sharp bounds for degree estimates on real…

Complex Variables · Mathematics 2009-03-13 John P. D'Angelo , Jiri Lebl

We construct invariants of birational maps with values in the Kontsevich--Tschinkel group and in the truncated Grothendieck groups of varieties. These invariants are morphisms of groupoids and are well-suited to investigating the structure…

Algebraic Geometry · Mathematics 2023-06-13 Hsueh-Yung Lin , Evgeny Shinder

In this paper we study multilinear morphisms between commutative group schemes and the associated tensor constructions. We will also do some explicit calculations and give examples that show that this theory behaves in a way that one would…

Number Theory · Mathematics 2019-08-16 Mohammad Hadi Hedayatzadeh

It is a classical problem in algebraic geometry to characterize the algebraic subvariety by using the Gauss map. In this note, we try to develop the analogue theory in CR geometry. In particular, under some assumptions, we show that a CR…

Complex Variables · Mathematics 2018-06-26 Wanke Yin , Yuan Yuan , Yuan Zhang

We construct new invariants of equivariant birational isomorphisms taking values in equivariant Burnside groups.

Algebraic Geometry · Mathematics 2022-08-12 Andrew Kresch , Yuri Tschinkel

We study a cross-ratio of four generic points of $S^3$ which comes from spherical CR geometry. We construct a homomorphism from a certain group generated by generic configurations of four points in $S^3$ to the pre-Bloch group $\mathcal…

Geometric Topology · Mathematics 2014-12-25 Elisha Falbel , Qingxue Wang

We construct and study cluster algebra structures in rings of invariants of the special linear group action on collections of three-dimensional vectors, covectors, and matrices. The construction uses Kuperberg's calculus of webs on marked…

Quantum Algebra · Mathematics 2015-06-16 Sergey Fomin , Pavlo Pylyavskyy

We compute the invariant subspace of the rational group ring of a surface, truncated by powers of the augmentation ideal, under the action of the mapping class group. The surface is compact, oriented with one boundary component. This…

Geometric Topology · Mathematics 2025-10-02 Andreas Stavrou

We construct tree-decompositions of graphs that distinguish all their k-blocks and tangles of order k, for any fixed integer k. We describe a family of algorithms to construct such decompositions, seeking to maximize their diversity subject…

Combinatorics · Mathematics 2014-04-25 Johannes Carmesin , Reinhard Diestel , Matthias Hamann , Fabian Hundertmark

Recently continuous rational maps between real algebraic varieties have attracted the attention of several researchers. In this paper we continue the investigation of approximation properties of continuous rational maps with values in…

Algebraic Geometry · Mathematics 2015-12-21 Wojciech Kucharz , Krzysztof Kurdyka

Using equivariant obstruction theory we construct equivariant maps from certain classifying spaces to representation spheres for cyclic groups, product of elementary Abelian groups and dihedral groups. Restricting them to finite skeleta…

Algebraic Topology · Mathematics 2016-07-22 Samik Basu , Surojit Ghosh

We analyze in this paper a random feature map based on a theory of invariance I-theory introduced recently. More specifically, a group invariant signal signature is obtained through cumulative distributions of group transformed random…

Machine Learning · Computer Science 2015-12-07 Youssef Mroueh , Stephen Voinea , Tomaso Poggio

We investigate the integrals of motion of general conformal mechanical systems with and without confining harmonic potential as well as of the related angular subsystems, by employing the SL(2,R) algebra and its representations. In…

High Energy Physics - Theory · Physics 2015-06-18 Tigran Hakobyan , David Karakhanyan , Olaf Lechtenfeld

Random intersection graphs model networks with communities, assuming an underlying bipartite structure of groups and individuals, where these groups may overlap. Group memberships are generated through the bipartite configuration model.…

Probability · Mathematics 2026-01-14 Remco van der Hofstad , Julia Komjathy , Viktoria Vadon

In this paper, we survey recent works on the structure of the mapping class groups of surfaces mainly from the point of view of topology. We then discuss several possible directions for future research. These include the relation between…

Geometric Topology · Mathematics 2016-09-07 Shigeyuki Morita

We provide formulas for invariants defined on a tensor product of defining representations of unitary groups, under the action of the product group. This situation has a physical interpretation, as it is related to the quantum mechanical…

Representation Theory · Mathematics 2011-11-01 Michael W. Hero , Jeb F. Willenbring , Lauren Kelly Williams

We consider each of the three classes of representations of cyclic groups that arise in the study of rational sphere maps. We study the possible number of terms for invariant polynomials with non-negative coefficients that are constant on…

Complex Variables · Mathematics 2025-12-08 John P. D'Angelo , Dusty E. Grundmeier , Daniel A. Lichtblau
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