Results 61 to 70 of about 12,740,858 (240)

Cohomology classes of rank varieties and a counterexample to a conjecture of Liu [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2015
To each finite subset of a discrete grid $\mathbb{N}×\mathbb{N}$ (a diagram), one can associate a subvariety of a complex Grassmannian (a diagram variety), and a representation of a symmetric group (a Specht module).
Brendan Pawlowski
doaj   +1 more source

Commutative formal groups arising from schemes

open access: yes, 2014
We prove the following criterion for the pro-representability of the deformation cohomology of a commutative formal Lie group. Let f be a flat and separated morphism between noetherian schemes. Assume that the target of f is flat over the integers. For a
Chatzistamatiou, Andre
core   +1 more source

FTheoryTools: Advancing Computational Capabilities for F‐Theory Research

open access: yesFortschritte der Physik, Volume 74, Issue 1, January 2026.
Abstract A primary goal of string phenomenology is to identify realistic four‐dimensional physics within the landscape of string theory solutions. In F‐theory, such solutions are encoded in the geometry of singular elliptic fibrations, whose study often requires particularly challenging and cumbersome computations.
Martin Bies   +2 more
wiley   +1 more source

When do pseudo‐Gorenstein rings become Gorenstein?

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We discuss the relationship between the trace ideal of the canonical module and pseudo‐Gorensteinness. In particular, under certain mild assumptions, we show that every positively graded domain that is both pseudo‐Gorenstein and nearly Gorenstein is Gorenstein. As an application, we clarify the relationships among nearly Gorensteinness, almost
Sora Miyashita
wiley   +1 more source

The Hartshorne-Rao module of curves on rational normal scrolls

open access: yesLe Matematiche, 2000
We study the Hartshorne-Rao module of curves lying on a rational normal scroll S_e of invariant e ≥ 0 in P^{e+3} .We calculate the Rao function, we characterize the aCM curves on S_e .Finally, we give an algorithm to check if a curve is aC M or not and ...
Roberta Di Gennaro
doaj  

Type II string theory on Calabi-Yau manifolds with torsion and non-Abelian discrete gauge symmetries

open access: yesJournal of High Energy Physics, 2017
We provide the first explicit example of Type IIB string theory compactification on a globally defined Calabi-Yau threefold with torsion which results in a four-dimensional effective theory with a non-Abelian discrete gauge symmetry. Our example is based
Volker Braun   +3 more
doaj   +1 more source

The log Grothendieck ring of varieties

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We define a Grothendieck ring of varieties for log schemes. It is generated by one additional class “P$P$” over the usual Grothendieck ring. We show the naïve definition of log Hodge numbers does not make sense for all log schemes. We offer an alternative that does.
Andreas Gross   +4 more
wiley   +1 more source

Cohomology-Developed Matrices -- constructing families of weighing matrices and automorphism actions

open access: yes, 2020
The aim of this work is to construct families of weighing matrices via their automorphism group action. This action is determined from the $0,1,2$-cohomology groups of the underlying abstract group. As a consequence, some old and new families of weighing
Goldberger, Assaf
core  

Profinite direct sums with applications to profinite groups of type ΦR$\Phi _R$

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract We show that the ‘profinite direct sum’ is a good notion of infinite direct sums for profinite modules, having properties similar to those of direct sums of abstract modules. For example, the profinite direct sum of projective modules is projective, and there is a Mackey's formula for profinite modules described using these sums.
Jiacheng Tang
wiley   +1 more source

Representations on Hessenberg Varieties and Young's Rule [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2011
We combinatorially construct the complex cohomology (equivariant and ordinary) of a family of algebraic varieties called regular semisimple Hessenberg varieties. This construction is purely in terms of the Bruhat order on the symmetric group. From this a
Nicholas Teff
doaj   +1 more source

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