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We obtain a rigidity phenomena of rational cohomology automorphisms of certain homogeneous spaces, in the presence of external cohomology classes arising from spaces with trivial cup product in rational cohomology algebra. We classify…

Algebraic Topology · Mathematics 2026-04-01 Manas Mandal , Divya Setia

We introduce a new class of zero-dimensional weighted complete intersections, by abstracting the essential features of rational cohomology algebras of equal rank homogeneous spaces of compact connected Lie groups. We prove that, on a…

Differential Geometry · Mathematics 2007-12-11 Stefan Papadima , Laurentiu Paunescu

F. Podest\`a and A. Spiro introduced a class of $G$-manifolds $M$ with a cohomogeneity one action of a compact semisimple Lie group $G$ which admit an invariant Kaehler structure $(g,J)$ (``standard $G$-manifolds") and studied invariant…

Differential Geometry · Mathematics 2019-06-26 Dmitri Alekseevsky , Fabio Zuddas

We combine and exploit ideas from Coset Space Dimensional Reduction (CSDR) methods and Non-commutative Geometry. We consider the dimensional reduction of gauge theories defined in high dimensions where the compact directions are a fuzzy…

High Energy Physics - Theory · Physics 2009-11-10 P. Aschieri , J. Madore , P. Manousselis , G. Zoupanos

The number of singularities, counted with multiplicity, of a generic codimension one holomorphic distribution on a compact toric orbifold is determined. As a consequence, we give the classification of regular distributions on rational…

Complex Variables · Mathematics 2024-02-28 Miguel Rodríguez Peña

Let $G$ be a connected, simply connected, simple, complex, linear algebraic group. Let $P$ be an arbitrary parabolic subgroup of $G$. Let $X=G/P$ be the $G$-homogeneous projective space attached to this situation. We consider the (small)…

Algebraic Geometry · Mathematics 2016-12-14 Christoph Bärligea

For any integer $d\in \mathbb{Z}$ we introduce a complex $\mathsf{ORGC}_{d}^{(g,m)}$ spanned by genus $g$ ribbon quivers with $m$ marked boundaries and prove that its cohomology computes (up to a degree shift) the compactly supported…

Algebraic Geometry · Mathematics 2025-04-10 Sergei Merkulov

Motivated by various results on homogeneous geodesics of Riemannian spaces, we study homogeneous trajectories, i.e. trajectories which are orbits of a one-parameter symmetry group, of Lagrangian and Hamiltonian systems. We present criteria…

Mathematical Physics · Physics 2010-08-20 Gabor Zsolt Toth

In this article we provide a version of the Leray-Serre spectral sequence for equidimensional (i.e. smooth with all orbits of the same dimension) actions of compact connected Lie groups on compact manifolds. The main part of this article…

Algebraic Topology · Mathematics 2025-10-24 Paweł Raźny

We extend the celebrated rigidity of the sharp first spectral gap under $Ric\ge0$ to compact infinitesimally Hilbertian spaces with non-negative (weak, also called synthetic) Ricci curvature and bounded (synthetic) dimension i.e. to…

Differential Geometry · Mathematics 2023-05-09 Christian Ketterer , Yu Kitabeppu , Sajjad Lakzian

In this note we describe a family of arguments that link the homotopy-type of a) the diffeomorphism group of the disc $D^n$, b) the space of co-dimension one embedded spheres in a sphere and c) the homotopy-type of the space of co-dimension…

Geometric Topology · Mathematics 2024-07-12 Ryan Budney

Let $U$ be a horospherical subgroup of a noncompact simple Lie group $H$ and let $A$ be a maximal split torus in the normalizer of $U$. We define the expanding cone $A_U^+$ in $A$ with respect to $U$ and show that it can be explicitly…

Dynamical Systems · Mathematics 2019-02-04 Ronggang Shi

We prove that a compact stratied space satises the Riemannian curvature-dimension condition RCD(K, N) if and only if its Ricci tensor is bounded below by K $\in$ R on the regular set, the cone angle along the stratum of codimension two is…

Differential Geometry · Mathematics 2018-06-11 J. Bertrand , C Ketterer , Ilaria Mondello , T. Richard

In this paper, we extend our previous analysis concerning the formation of inhomogeneous condensates in strongly-coupled fermion effective field theories on curved spaces and include the case of conifold geometries that represent the…

High Energy Physics - Theory · Physics 2015-06-03 Antonino Flachi

We study compact group actions with finite Rokhlin dimension, particularly in relation to crossed products. For example, we characterize the duals of such actions, generalizing previous partial results for the Rokhlin property. As an…

Operator Algebras · Mathematics 2020-10-01 Eusebio Gardella , Ilan Hirshberg , Luis Santiago

The projective linear group $\text{PGL}(3)$ naturally acts on the Grassmannian $\text{Gr}(3, V_2)$ of $3$-dimensional subspaces of the vector space $V_2$ of homogeneous conics in 3 variables. It was proved by Abdallah, Emsalem and Iarrobino…

Algebraic Geometry · Mathematics 2025-07-25 Tanav Choudhary

We establish a connection between continuous K-theory and integral cohomology of rigid spaces. Given a rigid analytic space over a complete discretely valued field, its continuous K-groups vanish in degrees below the negative of the…

K-Theory and Homology · Mathematics 2024-03-05 Christian Dahlhausen

When a discrete group admits a convex-cocompact action on a non-compact rank-one symmetric space, there is a natural lower bound for the Hausdorff dimension of the limit set, given by the Ahlfors regular conformal dimension of the boundary…

Metric Geometry · Mathematics 2018-06-13 Guy C. David , Kyle Kinneberg

We show that for a parabolic R^d-action on a compact quotient of PSL(2,R)^d, the cohomologies in degrees 1 through d-1 trivialize, and we give the obstructions to solving the degree-d coboundary equation, along with bounds on Sobolev norms…

Dynamical Systems · Mathematics 2017-08-16 Felipe A. Ramirez

The article is devoted to the question whether the orbit space of a compact linear group is a topological manifold and a homological manifold. In the paper, the case of a simple three-dimensional group is considered. An upper bound is…

Algebraic Geometry · Mathematics 2022-05-05 O. G. Styrt