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We classify valuations on lattice polygons with values in the ring of formal power series that commute with the action of the affine unimodular group. A typical example of such valuations is induced by the Laplace transform, but as it turns…

Metric Geometry · Mathematics 2025-10-07 Karoly J. Boroczky , Matyas Domokos , Ansgar Freyer , Christoph Haberl , Jin Li

In this short paper we first recall the definition and the construction of the fundamental group scheme of a scheme $X$ in the known cases: when it is defined over a field and when it is defined over a Dedekind scheme. It classifies all the…

Algebraic Geometry · Mathematics 2015-11-24 Marco Antei

Duality for complete discrete valuation fields with perfect residue field with coefficients in (possibly p-torsion) finite flat group schemes was obtained by Begueri, Bester and Kato. In this paper, we give another formulation and proof of…

Number Theory · Mathematics 2022-11-21 Takashi Suzuki

Let $X$ be a nonempty real variety that is invariant under the action of a reflection group $G$. We conjecture that if $X$ is defined in terms of the first $k$ basic invariants of $G$ (ordered by degree), then $X$ meets a $k$-dimensional…

Algebraic Geometry · Mathematics 2017-06-08 Tobias Friedl , Cordian Riener , Raman Sanyal

We establish normal form theorems for a large class of singular flat connections on complex manifolds, including connections with logarithmic poles along weighted homogeneous Saito free divisors. As a result, we show that the moduli spaces…

Algebraic Geometry · Mathematics 2022-09-02 Francis Bischoff

We apply the local removable singularity theorem for minimal laminations and the local picture theorem on the scale of topology to obtain two descriptive results for certain possibly singular minimal laminations of $\mathbb{R}^3$. These two…

Differential Geometry · Mathematics 2016-11-24 William H. Meeks , Joaquin Perez , Antonio Ros

The article gives the second part of the treatise on Regular Algebraic $K$-theory (Sections V & VI) of the author. Regular algebraic $K$-theory for groups is a homology theory for discrete groups closely connected to (but different from)…

K-Theory and Homology · Mathematics 2024-10-11 Ulrich Haag

In this article we work out the details of flat groups of the automorphism group of locally finite Bruhat-Tits buildings.

Group Theory · Mathematics 2025-12-19 Sebastian Bischof

We classify localising subcategories of the stable module category of a finite group that are closed under tensor product with simple (or, equivalently all) modules. One application is a proof of the telescope conjecture in this context.…

Representation Theory · Mathematics 2011-04-18 Dave Benson , Srikanth B. Iyengar , Henning Krause

We study the positive theory of groups acting on trees and show that under the presence of weak small cancellation elements, the positive theory of the group is trivial, i.e. coincides with the positive theory of a non-abelian free group.…

Group Theory · Mathematics 2019-10-22 Montserrat Casals-Ruiz , Albert Garreta , Javier de la Nuez González

Flatness of discrete-time systems can be characterized by two simple properties. There exists a map, a submersion, from the flat coordinates and their forward shifts to the state and the input of the discrete-time system, such that the…

Differential Geometry · Mathematics 2023-03-10 Schlacher Kurt , Lindorfer Martin

We review the concept of differentiably simple ring and we give a new proof of Harper's Theorem on the characterization of Noetherian differentiably simple rings in positive characteristic. We then study flat families of differentiably…

Commutative Algebra · Mathematics 2024-10-08 Celia del Buey de Andrés , Diego Sulca , Orlando E. Villamayor

Support $\tau$-tilting modules correspond to some classes of categorical objects bijectively, such as two-term tilting complexes for any finite dimensional symmetric algebra. This fact motivates us to classify support $\tau$-tilting modules…

Representation Theory · Mathematics 2020-04-28 Ryotaro Koshio , Yuta Kozakai

We prove a division algorithm for group rings of high genus surface groups and use it to show that some $2$-complexes with surface fundamental groups are standard. We also give an application of division to cohomological dimension of…

Geometric Topology · Mathematics 2021-01-05 Grigori Avramidi

Let F be a global field, A its ring of adeles, G a reductive group over F. We prove the Baum-Connes conjecture for the adelic group G(A).

K-Theory and Homology · Mathematics 2009-10-31 Paul Baum , Stephen Millington , Roger Plymen

Fix a flat and projective morphism $X\rightarrow\Sigma$ of schemes. We show, first, that any set of $\mathbb{P}^1$-fibrations on $X$ defines a set of simple roots, a set of simple coroots and a Cartan matrix $C$. Second, $X$ is an \'etale…

Algebraic Geometry · Mathematics 2025-09-15 I. Grojnowski , N. I. Shepherd-Barron

We consider parahoric Bruhat-Tits group schemes over a smooth projective curve and torsors under them. If the characteristic of the ground field is either zero or positive but not too small and the generic fiber is absolutely simple and…

Algebraic Geometry · Mathematics 2023-11-01 Georgios Pappas , Michael Rapoport

The analogue of Goldie's Theorem for prime rings is proved for rings graded by abelian groups, eliminating unnecessary additional hypotheses used in earlier versions.

Rings and Algebras · Mathematics 2007-05-23 K. R. Goodearl , J. T. Stafford

We extend the minimal model theorem to the 3-dimensional schemes which are projective and have semistable reduction over the spectrum of a Dedekind ring.

alg-geom · Mathematics 2008-02-03 Yujiro Kawamata

Let O_K be a discrete valuation ring of mixed characteristics (0,p), with residue field k. Using work of Sekiguchi and Suwa, we construct some finite flat O_K-models of the group scheme \mu_{p^n,K} of p^n-th roots of unity, which we call…

Number Theory · Mathematics 2013-01-15 Ariane Mézard , Matthieu Romagny , Dajano Tossici