Results 31 to 40 of about 4,761 (119)
Vector bundles on bielliptic surfaces: Ulrich bundles and degree of irrationality
Abstract This paper deals with two problems about vector bundles on bielliptic surfaces. The first is to give a classification of Ulrich bundles on such surfaces S$S$, which depends on the topological type of S$S$. In doing so, we study the weak Brill–Noether property for moduli spaces of sheaves with isotropic Mukai vector. Adapting an idea of Moretti
Edoardo Mason
wiley +1 more source
A Re‐Examination of Foundational Elements of Cosmology
ABSTRACT This paper undertakes a conceptual re‐examination of several foundational elements of cosmology through the lens of spacetime symmetries. A new derivation of the Friedmann–Lemaître–Robertson–Walker metric is obtained by a careful conceptual examination of rotations and translations on generic manifolds, followed by solving the rotational and ...
Lavinia Heisenberg
wiley +1 more source
Homology class of a Lagrangian Klein bottle
It is shown that an embedded Lagrangian Klein bottle represents a non-trivial mod 2 homology class in a compact symplectic four-manifold $(X,\omega)$ with $c_1(X)\cdot[\omega]>0$. (In versions 1 and 2, the last assumption was missing. A counterexample to
+15 more
core +1 more source
Osculating geometry and higher‐order distance Loci
Abstract We discuss the problem of optimizing the distance function from a given point, subject to polynomial constraints. A key algebraic invariant that governs its complexity is the Euclidean distance degree, which pertains to first‐order tangency. We focus on the data locus of points possessing at least one critical point of the distance function ...
Sandra Di Rocco +2 more
wiley +1 more source
Amplified spontaneous emission (ASE) in difluoroboron‐based gain molecules is shown to originate from aggregated singlet states (S1), contradicting its previously assumed phosphorescent origin. Additionally, the delayed emission arises from a triplet–triplet annihilation upconversion (TTA‐UC) mechanism rather than a thermally activated (TADF) process ...
Suman Kuila +6 more
wiley +2 more sources
Harmonic maps to the circle with higher dimensional singular set
Abstract In a closed, oriented ambient manifold (Mn,g)$(M^n,g)$ we consider the problem of finding S1$\mathbb {S}^1$‐valued harmonic maps with prescribed singular set. We show that the boundary of any oriented (n−1)$(n-1)$‐submanifold can be realised as the singular set of an S1$\mathbb {S}^1$‐valued map, which is classically harmonic away from the ...
Marco Badran
wiley +1 more source
Dimer models and conformal structures
Abstract Dimer models have been the focus of intense research efforts over the last years. Our paper grew out of an effort to develop new methods to study minimizers or the asymptotic height functions of general dimer models and the geometry of their frozen boundaries.
Kari Astala +3 more
wiley +1 more source
Abstract Twistor spaces are certain compact complex three‐folds with an additional real fibre bundle structure. We focus here on twistor spaces over P2#P2#P2${\mathbb {P}}^2\#{\mathbb {P}}^2\#{\mathbb {P}}^2$. Such spaces are either small resolutions of double solids or they can be described as modifications of conic bundles.
Bernd Kreußler, Jan Stevens
wiley +1 more source
Toric amplitudes and universal adjoints
Abstract A toric amplitude is a rational function associated with a simplicial polyhedral fan. The definition is inspired by scattering amplitudes in particle physics. We prove algebraic properties of such amplitudes and study the geometry of their zero loci. These hypersurfaces play the role of Warren's adjoint via a dual volume interpretation.
Simon Telen
wiley +1 more source
Module structure of Weyl algebras
Abstract The seminal paper (Stafford, J. Lond. Math. Soc. (2) 18 (1978), no. 3, 429–442) was a major step forward in our understanding of Weyl algebras. Beginning with Serre's Theorem on free summands of projective modules and Bass' Stable Range Theorem in commutative algebra, we attempt to trace the origins of this work and explain how it led to ...
Gwyn Bellamy
wiley +1 more source

