Results 11 to 20 of about 623 (106)
Covalently linked carbazole dimers exhibit intense excimer‐based circularly polarized luminescence (CPL). A simple propylene‐tethered dimer achieves glum ≈ 0.01 in the violet region—among the highest for small organic emitters without heavy atoms. Conformational mapping reveals CPL is governed by thermodynamic/kinetic control of emissive conformers ...
Tomohiro Kujime, Zhe Wang, Tadashi Mori
wiley +2 more sources
Tachyons in “momentum-space” representation
Obtaining the momentum space associated with tachyonic “particles” from the Poincaré group manifold proves to be rather intricate, departing very much from the ordinary dual to Minkowski space directly parametrized by space-time translations of the ...
V. Aldaya, J. Guerrero, F.F. López-Ruiz
doaj +1 more source
Lightlike hypersurfaces in indefinite $\mathcal{S}$-manifolds
In a metric $g.f.f$-manifold we study lightlike hypersurfaces $M$ tangent to the characteristic vector fields, and owing to the presence of the $f$-structure, we determine some decompositions of $TM$ and of a chosen screen distribution obtaining two distributions invariant with respect to the structure.
Brunetti, Letizia, Pastore, Anna Maria
openaire +3 more sources
Rational points on even‐dimensional Fermat cubics
Abstract We show that even‐dimensional Fermat cubic hypersurfaces are rational over any field of characteristic not equal to three, by constructing explicit rational parameterizations with polynomials of low degree. As a byproduct of our rationality constructions, we obtain estimates for the number of their rational points over a number field and ...
Alex Massarenti
wiley +1 more source
Background Instability of Quintessence Model in Light of Entropy and Distance Conjecture
ABSTRACT We apply the covariant entropy bound argument supporting the de Sitter swampland conjecture to the quintessence model, to find out the condition for the background to be unstable. More concretely, the background is unstable when the matter entropy given by the species number of the effective field theory increases more rapidly than the ...
Min‐Seok Seo
wiley +1 more source
The singularity category and duality for complete intersection groups
Abstract If G$G$ is a finite group, the structure of the modular representation theory depends on the cochains C∗(BG;k)$C^*(BG; k)$, viewed as a commutative ring spectrum. We consider here its singularity category (in the sense of the author and Stevenson [Adv. Math.
J. P. C. Greenlees
wiley +1 more source
Cohomogeneity‐one solitons in Laplacian flow: Local, smoothly‐closing and steady solitons
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
Stochastic Dynamics From Maximum Entropy in Action Space
ABSTRACT We develop an information‐theoretic formulation of stochastic dynamics in which the fundamental stochastic variable is the total action connecting spacetime points, rather than individual paths. By maximizing Shannon entropy over a joint distribution of actions and endpoints, subject to normalization and a constraint on the mean action, we ...
Fabricio Souza Luiz +3 more
wiley +1 more source
The fundamental group of the complement of a generic fiber‐type curve
Abstract In this paper, we describe and characterize the fundamental group of the complement of generic fiber‐type curves, that is, unions of (the closure of) finitely many generic fibers of a component‐free pencil F=[f:g]:CP2⤍CP1$F=[f:g]:\mathbb {C}\mathbb {P}^2\dashrightarrow \mathbb {C}\mathbb {P}^1$.
José I. Cogolludo‐Agustín +1 more
wiley +1 more source
Which singular tangent bundles are isomorphic?
Abstract Logarithmic and b$ b$‐tangent bundles provide a versatile framework for addressing singularities in geometry. Introduced by Deligne and Melrose, these modified bundles resolve singularities by reframing singular vector fields as well‐behaved sections of these singular bundles.
Eva Miranda, Pablo Nicolás
wiley +1 more source

