Results 21 to 30 of about 18,981 (110)

Toral symmetries of collapsed ancient solutions to the homogeneous Ricci flow

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract Collapsed ancient solutions to the homogeneous Ricci flow on compact manifolds occur only on the total space of principal torus bundles. Under an algebraic assumption that guarantees flowing through diagonal metrics and a tameness assumption on the collapsing directions, we prove that such solutions have additional symmetries, that is, they ...
Anusha M. Krishnan, Francesco Pediconi, Sammy Sbiti   +2 more
wiley   +1 more source

Tempered Representations and Nilpotent Orbits [PDF]

, 2015
Given a nilpotent orbit O of a real, reductive algebraic group, a necessary condition is given for the existence of a tempered representation pi such that O occurs in the wave front cycle of pi.
Harris, Benjamin
core  

On the intersections of nilpotent subgroups in simple groups

Proceedings of the London Mathematical Society, Volume 132, Issue 3, March 2026.
Abstract Let G$G$ be a finite group and let Hp$H_p$ be a Sylow p$p$‐subgroup of G$G$. A recent conjecture of Lisi and Sabatini asserts the existence of an element x∈G$x \in G$ such that Hp∩Hpx$H_p \cap H_p^x$ is inclusion‐minimal in the set {Hp∩Hpg:g∈G}$\lbrace H_p \cap H_p^g \,:\, g \in G\rbrace$ for every prime p$p$.
Timothy C. Burness, Hong Yi Huang
wiley   +1 more source

Polar orthogonal representations of real reductive algebraic groups

, 2008
We prove that a polar orthogonal representation of a real reductive algebraic group has the same closed orbits as the isotropy representation of a pseudo-Riemannian symmetric space.
Geatti, Laura, Gorodski, Claudio
core   +2 more sources

Entropy rigidity for cusped Hitchin representations

Journal of Topology, Volume 19, Issue 1, March 2026.
Abstract We establish an entropy rigidity theorem for Hitchin representations of geometrically finite Fuchsian groups which generalizes a theorem of Potrie and Sambarino for Hitchin representations of closed surface groups. In the process, we introduce the class of (1,1,2)‐hypertransverse groups and show for such a group that the Hausdorff dimension of
Richard Canary, Tengren Zhang, Andrew Zimmer   +2 more
wiley   +1 more source

Semi-direct products of Lie algebras and their invariants

, 2007
The goal of this paper is to extend the standard invariant-theoretic design, well-developed in the reductive case, to the setting of representation of certain non-reductive groups. This concerns the following notions and results: the existence of generic
Panyushev, Dmitri I.
core   +1 more source

The versal deformation of small resolutions of conic bundles over P1×P1${\mathbb {P}}^1\times {\mathbb {P}}^1$ with two sections blown down

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract Twistor spaces are certain compact complex three‐folds with an additional real fibre bundle structure. We focus here on twistor spaces over P2#P2#P2${\mathbb {P}}^2\#{\mathbb {P}}^2\#{\mathbb {P}}^2$. Such spaces are either small resolutions of double solids or they can be described as modifications of conic bundles.
Bernd Kreußler, Jan Stevens
wiley   +1 more source

Derangements in intransitive groups

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract Let G$G$ be a nontrivial permutation group of degree n$n$. If G$G$ is transitive, then a theorem of Jordan states that G$G$ has a derangement. Equivalently, a finite group is never the union of conjugates of a proper subgroup. If G$G$ is intransitive, then G$G$ may fail to have a derangement, and this can happen even if G$G$ has only two ...
David Ellis, Scott Harper
wiley   +1 more source

An asymptotic local–global theorem on heights of some Kleinian group orbits

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract We prove an asymptotic local–global theorem on the heights of point orbits of thin subgroups of Bianchi groups in H3$\mathbb {H}^3$.
Xuanxuan Xiao, Xin Zhang
wiley   +1 more source

Alperin's bound and normal Sylow subgroups

Journal of the London Mathematical Society, Volume 113, Issue 2, February 2026.
Abstract Let G$G$ be a finite group, p$p$ a prime number and P$P$ a Sylow p$p$‐subgroup of G$G$. Recently, Malle, Navarro, and Tiep conjectured that the number of p$p$‐Brauer characters of G$G$ coincides with that of the normalizer NG(P)${\bf N}_G(P)$ if and only if P$P$ is normal in G$G$.
Zhicheng Feng, J. Miquel Martínez, Damiano Rossi   +2 more
wiley   +1 more source