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Related papers: Relative twisting in Outer space

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The so-called Tits class, associated to an adjoint absolutely almost simple algebraic group, provides a cohomological obstruction for this group to admit an outer automorphism. If the group has inner type, this obstruction is the only one.…

Group Theory · Mathematics 2016-10-18 Anne Quéguiner-Mathieu , Jean-Pierre Tignol

We consider smooth plane curves $\mathcal{X}$ of degree $d\geq4$, defined over an algebraically closed field of characteristic $0$, that possess a unique outer Galois point. This geometric condition forces the curve to be a cyclic covering…

Algebraic Geometry · Mathematics 2026-03-30 Eslam Badr , Takeshi Harui

In the literature on X-ray transform and Transport Twistor (TT) spaces, blow-down maps (or maps with holomorphic blow-down structure as defined in [BMP24]) are maps that desingularize the degenerate complex structure of the TT space of an…

Differential Geometry · Mathematics 2025-10-13 François Monard , Zhengyi Qi

The curvature discussed in this paper is a rather far going generalization of the Riemannian sectional curvature. We define it for a wide class of optimal control problems: a unified framework including geometric structures such as…

Differential Geometry · Mathematics 2018-11-30 Andrei Agrachev , Davide Barilari , Luca Rizzi

We derive formulas for the mean curvature of associative 3-folds, coassociative 4-folds, and Cayley 4-folds in the general case where the ambient space has intrinsic torsion. Consequently, we are able to characterize those G2-structures…

Differential Geometry · Mathematics 2019-09-19 Gavin Ball , Jesse Madnick

We study when the mapping class group of an infinite-type surface $S$ admits an action with unbounded orbits on a connected graph whose vertices are simple closed curves on $S$. We introduce a topological invariant for infinite-type…

Geometric Topology · Mathematics 2024-03-11 Matthew Gentry Durham , Federica Fanoni , Nicholas G. Vlamis

We deal with irregular curves contained in smooth, closed, and compact surfaces. For curves with finite total intrinsic curvature, a weak notion of parallel transport of tangent vector fields is well-defined in the Sobolev setting. Also,…

Differential Geometry · Mathematics 2021-05-17 Domenico Mucci , Alberto Saracco

A model invariant under a supersymmetric extension of the rotation group O(3) is mapped, using a stereographic projection, from the spherical surface S2 to two dimensional Euclidean space. The resulting model does not have a manifest local…

General Physics · Physics 2018-05-23 D. G. C. McKeon

Motivated by the problem of defining the entanglement entropy of the graviton, we study the division of the phase space of general relativity across subregions. Our key requirement is demanding that the separation into subregions is…

High Energy Physics - Theory · Physics 2019-02-20 Joan Camps

In this paper, we study the curvature properties of random complex plane curves. We bound from below the probability that a uniform proportion of the area of a random complex degree $d$ plane curve has a curvature smaller than $-d/8$. Our…

Algebraic Geometry · Mathematics 2024-02-20 Michele Ancona , Damien Gayet

Let $A_1,...,A_k$ be a system of free factors of $F_n$. The group of relative automorphisms $Aut(F_n;A_1,...,A_k)$ is the group given by the automorphisms of $F_n$ that restricted to each $A_i$ are conjugations by elements in $F_n$. The…

Geometric Topology · Mathematics 2011-04-21 Erika Meucci

We determine that the deformation space of convex real projective structures, that is, projectively flat torsion-free connections with the geodesic convexity property on a compact 2-orbifold of negative Euler characteristic is homeomorphic…

Geometric Topology · Mathematics 2011-07-12 Suhyoung Choi , William Goldman

If the universe has a nontrivial shape (topology) the sky may show multiple correlated images of cosmic objects. These correlations can be couched in terms of distance correlations. We propose a statistical quantity which can be used to…

General Relativity and Quantum Cosmology · Physics 2009-11-07 G. I. Gomero , M. J. Reboucas , A. F. F. Teixeira

We construct solitons in affine orbifold nets associated with outer automorphisms, and we show that our construction gives all the twisted representations of the fixed point subnet. This allows us to settle a number of questions concerning…

Operator Algebras · Mathematics 2010-02-16 Feng Xu

We discuss the geometry of the c-map from projective special K\"ahler to quaternionic K\"ahler manifolds using the twist construction to provide a global approach to Hitchin's description. As found by Alexandrov et al. and Alekseevsky et…

Differential Geometry · Mathematics 2015-06-19 Oscar Macia , Andrew Swann

In the present paper we study twisted foldings of root systems which generalize usual involutive foldings corresponding to automorphisms of Dynkin diagrams. Our motivating example is the Lusztig projection of the root system of type $E_8$…

Algebraic Geometry · Mathematics 2019-11-25 Martina Lanini , Kirill Zainoulline

As a contribution to the ongoing discussion of trajectories of spinless particles in spaces with torsion we show that the geometry of such spaces can be induced by embedding their curves in a euclidean space without torsion. Technically…

General Relativity and Quantum Cosmology · Physics 2009-10-30 H. Kleinert , S. V. Shabanov

The formulation of gravity theory is considered where space-time is a 4-dimensional surface in flat ten-dimensional space. The possibility of using the "external" time (the time of ambient space) in this approach is investigated. The…

General Relativity and Quantum Cosmology · Physics 2015-09-07 S. A. Paston , E. N. Semenova

A study of rational maps of the real or complex projective plane of degree two or more, concentrating on those which map an elliptic curve onto itself, necessarily by an expanding map. We describe relatively simple examples with a rich…

Dynamical Systems · Mathematics 2007-05-23 Araceli Bonifant , Marius Dabija , John Milnor

In this paper, we investigate geometric conditions for isometric immersions with positive index of relative nullity to be cylinders. There is an abundance of noncylindrical $n$-dimensional minimal submanifolds with index of relative nullity…

Differential Geometry · Mathematics 2020-04-30 A. E. Kanellopoulou , Th. Vlachos