Results 71 to 80 of about 26,527 (250)
Splitting the difference: Computations of the Reynolds operator in classical invariant theory
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract If G$G$ is a linearly reductive group acting rationally on a polynomial ring S$S$, then the inclusion SG↪S$S^{G} \hookrightarrow S$ possesses a unique G$G$‐equivariant splitting, called the Reynolds operator. We describe algorithms for computing the Reynolds operator for the classical actions as in Weyl's book.
Aryaman Maithani
wiley +1 more source
On the geometry of the orthogonal momentum amplituhedron
Journal of High Energy Physics, 2022 In this paper we focus on the orthogonal momentum amplituhedron O $$ \mathcal{O} $$ k , a recently introduced positive geometry that encodes the tree-level scattering amplitudes in ABJM theory.
Tomasz Łukowski +2 more
doaj +1 more source
Canonical forms of oriented matroids
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract Positive geometries are semialgebraic sets equipped with a canonical differential form whose residues mirror the boundary structure of the geometry. Every full‐dimensional projective polytope is a positive geometry. Motivated by the canonical forms of polytopes, we construct a canonical form for any tope of an oriented matroid inside the Orlik–
Christopher Eur, Thomas Lam
wiley +1 more source
Splitting criteria for vector bundles on the symplectic isotropic Grassmannian
Le Matematiche, 2009 We extend a theorem of Ottaviani on cohomological splitting criterion for vector bundles over the Grassmannian to the case of the symplectic isotropic Grassmanian.
Pedro Macias Marques, Luke Oeding
doaj
Notes on polytopes, amplitudes and boundary configurations for Grassmannian string integrals
Journal of High Energy Physics, 2020 We continue the study of positive geometries underlying the Grassmannian string integrals, which are a class of “stringy canonical forms”, or stringy integrals, over the positive Grassmannian mod torus action, G +(k, n)/T .
Song He, Lecheng Ren, Yong Zhang
doaj +1 more source
Equivariant Giambelli formula for the symplectic Grassmannians — Pfaffian Sum Formula [PDF]
Discrete Mathematics & Theoretical Computer Science, 2015 We prove an explicit closed formula, written as a sum of Pfaffians, which describes each equivariant Schubert class for the Grassmannian of isotropic subspaces in a symplectic vector ...
Takeshi Ikeda, Tomoo Matsumura
doaj +1 more source
Geometric Poisson brackets on Grassmannians and conformal spheres [PDF]
, 2009 In this paper we relate the geometric Poisson brackets on the Grassmannian of 2-planes in R^4 and on the (2,2) Moebius sphere. We show that, when written in terms of local moving frames, the geometric Poisson bracket on the Moebius sphere does not ...
Beffa, G. Mari, Eastwood, M.
core +1 more source
, 2002 Noncommutative geometry governs the physics of quantum Hall (QH) effects. We introduce the Weyl ordering of the second quantized density operator to explore the dynamics of electrons in the lowest Landau level. We analyze QH systems made of $N$-component
A. Cappelli +35 more
core +1 more source
Inequalities and counterexamples for functional intrinsic volumes and beyond
Journal of the London Mathematical Society, Volume 113, Issue 1, January 2026.Abstract We show that analytic analogs of Brunn–Minkowski‐type inequalities fail for functional intrinsic volumes on convex functions. This is demonstrated both through counterexamples and by connecting the problem to results of Colesanti, Hug, and Saorín Gómez.
Fabian Mussnig, Jacopo Ulivelli
wiley +1 more source
Unification of Residues and Grassmannian Dualities
, 2010 The conjectured duality relating all-loop leading singularities of n-particle N^(k-2)MHV scattering amplitudes in N=4 SYM to a simple contour integral over the Grassmannian G(k,n) makes all the symmetries of the theory manifest.
A Brandhuber +40 more
core +1 more source