Results 41 to 50 of about 384 (152)

Cluster-projected matrix product state: Framework for engineering exact quantum many-body ground states in one and two dimensions

open access: yesPhysical Review Research
We propose a framework to design concurrently a frustration-free quantum many-body Hamiltonian and its numerically exact ground states on a sufficiently large finite-size cluster in one and two dimensions using an elementary matrix product state (MPS ...
Hidehiro Saito, Chisa Hotta
doaj   +1 more source

Algebraic Observability of Rational Systems

open access: yesProceedings in Applied Mathematics and Mechanics, Volume 26, Issue 2, June 2026.
ABSTRACT For nonlinear systems, the concept of observability is defined by the indistinguishability of states. In the practical implementation, the distinguishing of states is carried out via the observability map consisting of Lie derivatives. This approach is comparatively difficult for general nonlinear systems.
Klaus Röbenack, Daniel Gerbet
wiley   +1 more source

Leaf of leaf foliation and Beltrami parametrization in d > 2 dimensional gravity

open access: yesNuclear Physics B
This work establishes the existence of a covariant “Beltrami vielbein” in dimensions d>2, generalizing the well-known d=2 case. The definition of this vielbein is motivated by a sub-foliation structure of the Arnowitt–Deser–Misner (ADM) slices of a d ...
Laurent Baulieu
doaj   +1 more source

On submanifolds in locally symmetric spaces of noncompact type [PDF]

open access: yesAlgebraic & Geometric Topology, 2006
This is the version published by Algebraic & Geometric Topology on 15 December ...
Lafont, Jean-François   +1 more
openaire   +3 more sources

Counting Degrees of Freedom: A Method Applicable From Scalars to f(Q)$f(\mathbb {Q})$ Gravity and Beyond

open access: yesFortschritte der Physik, Volume 74, Issue 6, June 2026.
ABSTRACT We present a clear, step‐by‐step method for counting degrees of freedom and identifying constraints in general field theories. This approach, grounded in the works of Einstein, Hilbert, Cartan, Kuranishi, and, more recently, Seiler, is neither Lagrangian nor Hamiltonian in nature. Instead, it applies directly to the field equations. We offer a
Lavinia Heisenberg
wiley   +1 more source

On the tightness of left‐invariant contact structures

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 6, June 2026.
Abstract We prove that all left‐invariant contact structures on three‐dimensional Lie groups are tight. The argument is based on Riemannian methods and establishes a unique factorization property for any Lie group admitting a left‐invariant contact structure, other than SU(2)$\mathrm{SU}(2)$. We then make use of such factorization property to construct
Eugenio Bellini
wiley   +1 more source

Cohomogeneity‐one solitons in Laplacian flow: Local, smoothly‐closing and steady solitons

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 6, June 2026.
Abstract We initiate a systematic study of cohomogeneity‐one solitons in Bryant's Laplacian flow of closed G2$\text{G}_2$‐structures on a 7‐manifold, motivated by the problem of understanding finite‐time singularities of that flow. Here, we focus on solitons with symmetry groups Sp(2)${\rm Sp}(2)$ and SU(3)${\rm SU}(3)$; in both cases, we prove the ...
Mark Haskins, Johannes Nordström
wiley   +1 more source

Standing waves of nonlinear Schrödinger systems with all attractive forces

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 6, June 2026.
Abstract Since the pioneering work of Lin and Wei on nonlinear Schrödinger systems of n$n$ components with interaction forces aij$a_{ij}$ between the i$i$‐th and j$j$‐th components for 1⩽i,j⩽n$1\leqslant i,j\leqslant n$, there have been numerous further developments in many directions. However, even in the simplest case where all interaction forces are
Jaeyoung Byeon
wiley   +1 more source

Infinity‐operadic foundations for embedding calculus

open access: yesJournal of Topology, Volume 19, Issue 2, June 2026.
Abstract Motivated by applications to spaces of embeddings and automorphisms of manifolds, we consider a tower of ∞$\infty$‐categories of truncated right modules over a unital ∞$\infty$‐operad O$\mathcal {O}$. We study monoidality and naturality properties of this tower, identify its layers, describe the difference between the towers as O$\mathcal {O}$
Manuel Krannich, Alexander Kupers
wiley   +1 more source

Home - About - Disclaimer - Privacy