Results 111 to 120 of about 1,430 (227)

Indecomposable Direct Summands of Cohomologies of Curves

The Quarterly Journal of Mathematics
Abstract Groups with a non-cyclic Sylow p-subgroup have too many representations over a field of characteristic p to describe them fully. A natural question arises, whether the world of representations coming from algebraic varieties with a group action is as vast as the realm of all modular representations.
openaire   +3 more sources

Inference on Common Trends in a Cointegrated Nonlinear SVAR

Oxford Bulletin of Economics and Statistics, Volume 88, Issue 4, Page 658-676, August 2026.
ABSTRACT We consider the problem of performing inference on the number of common stochastic trends when data is generated by a cointegrated CKSVAR (a two‐regime, piecewise affine SVAR; Mavroeidis, 2021), using a modified version of the Breitung (2002) multivariate variance ratio test that is robust to the presence of nonlinear cointegration (of a known
James A. Duffy, Xiyu Jiao
wiley   +1 more source

A Generic Characterization of Direct Summands for Orthogonal Involutions [PDF]

Communications in Algebra, 2009
The `transcendental methods' in the algebraic theory of quadratic forms are based on two major results, proved in the 60's by Cassels and Pfister, and known as the representation and the subform theorems. A generalization of the representation theorem was proven by Jean-Pierre Tignol in 1996, in the setting of central simple algebras with involution ...
openaire   +2 more sources

Kitaoka's conjecture and sums of squares

Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.
Abstract We connect the existence of a ternary classical universal quadratic form over a totally real number field K$K$ with the property that all totally positive multiples of 2 are sums of squares (if K$K$ does not contain 2$\sqrt{2}$ or contains a nonsquare totally positive unit).
Vítězslav Kala, Kristýna Kramer, Jakub Krásenský   +2 more
wiley   +1 more source

The number of regular simplices in higher dimensions

Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.
Abstract We study the extremal function Sdk(n)$S^k_d(n)$, defined as the maximum number of regular (k−1)$(k-1)$‐simplices spanned by n$n$ points in Rd$\mathbb {R}^d$. For any fixed d⩾2k⩾6$d\geqslant 2k\geqslant 6$, we determine the asymptotic behavior of Sdk(n)$S^k_d(n)$ up to a lower‐order term.
Felix Christian Clemen, Adrian Dumitrescu, Dingyuan Liu   +2 more
wiley   +1 more source

Indecomposable decompositions and the minimal direct summand containing the nilpotents [PDF]

, 1979
It is well known that an indecomposable right ideal decomposition of a ring is not necessarily unique. In this paper we show that the reduced right ideals of such a decomposition are unique up to isomorphism and the remainder of the decomposition forms ...
G. F. Birkenmeier
core   +1 more source

When is the graph of a random 0/1 polytope a clique?

Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.
Abstract We study graph‐theoretic properties of random 0/1$0/1$ polytopes. Specifically, let Qpn⊆{0,1}n$Q_p^n \subseteq \lbrace 0,1\rbrace ^n$ be a random subset where each point is included independently with probability p$p$, and consider the graph Gp$G_p$ of the polytope conv(Qpn)$\operatorname{conv}(Q_p^n)$.
Catherine Babecki, Tycho Elling, Asaf Ferber   +2 more
wiley   +1 more source

Some Results on W-regular Rings

NTU Journal of Pure Sciences
Von Neumann regular rings, introduced in 1936, form a cornerstone of abstract algebra and were later extended to weakly regular rings. This work considers another extension, the W-regular rings defined by Wei [6], and explores their properties and ...
Hazim Tallat Hazim
doaj   +1 more source

A birational description of the minimal exponent

Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.
Abstract We give a description of the minimal exponent of a hypersurface using higher direct images of suitably twisted sheaves of log forms on a log resolution.
Qianyu Chen, Mircea Mustaţă
wiley   +1 more source

Finding an almost perfect matching in a hypergraph avoiding forbidden submatchings

Journal of the London Mathematical Society, Volume 114, Issue 2, August 2026.
Abstract In 1973, Erdős conjectured the existence of high girth (n,3,2)$(n,3,2)$‐Steiner systems. Recently, Glock, Kühn, Lo, and Osthus and independently Bohman and Warnke proved the approximate version of Erdős' conjecture. Recently, Kwan, Sah, Sawhney, and Simkin proved Erdős' conjecture.
Michelle Delcourt, Luke Postle
wiley   +1 more source