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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,657 papers · 148 categories

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121242363484 · May 202619922001200920172026
48 results for toric structures

A series of examples of toric Sasaki-Einstein 5-manifolds is constructed. These are submanifolds of toric 3-Sasaki 7-manifolds and such a Sasaki-Einstein 5-manifold corresponds uniquely to a toric 3-Sasaki 7-manifold. This produces examples of quasi-regular Sasaki-Einstein structures on every #k(S^2 xS^3), for k odd. T…

2007-03-16abs ↗pdf ↗

We introduce the cutting construction of possibly non-compact symplectic toric manifolds, in particular, toric symplectic cones that correspond to a weakly convex good cone. Since the symplectization of a toric contact manifold is a toric symplectic cone, we can also construct toric contact manifolds that correspond to…

2013-01-13abs ↗pdf ↗

Proves unique ALE instanton with toric Hermitian structure.

problem Classify Ricci flat ALE instantons with toric Hermitian non-Kähler structure.
method Direct global analysis of Tod form in Weyl-Papapetrou coordinates, avoiding toric Kähler geometry.
result Eguchi-Hanson instanton is the only smooth, Ricci flat, ALE instanton with toric Hermitian non-Kähler structure.

Anti-diagonal toric generalized Ka¨\ddot{a}hler structures of symplectic type on a compact toric symplectic manifold were investigated in \cite{Wang2} . In this article, we consider \emph{general} toric generalized Ka¨\ddot{a}hler structures of symplectic type, without requiring them to be anti-diagonal. Such a structu…

2018-11-14abs ↗pdf ↗

We prove that a compact toric locally conformally Kähler manifold which is not Kähler admits a toric Vaisman structure, a fact which was conjectured in \cite{mmp}. This is the final step leading to the classification of compact toric locally conformally Kähler manifolds started in \cite{p} and \cite{mmp}. We also show,…

2016-12-12abs ↗pdf ↗

An almost Kähler structure is {\it extremal} if the Hermitian scalar curvature is a Killing potential [29]. When the almost complex structure is integrable it coincides with extremal Kähler metric in the sense of Calabi [8]. We observe that the existence of an extremal {\it toric} almost Kähler structure of involutive …

2018-11-14abs ↗pdf ↗

Vaisman manifolds are strongly related to Kähler and Sasaki geometry. In this paper we introduce toric Vaisman structures and show that this relationship still holds in the toric context. It is known that the so-called minimal covering of a Vaisman manifold is the Riemannian cone over a Sasaki manifold. We show that if…

2015-12-02abs ↗pdf ↗

Study on non-archimedean μ-entropy for toric varieties, proving existence and uniqueness.

problem Exploring non-archimedean μ-entropy for toric varieties and its thermodynamical structure.
method Established a Rellich type compactness result for convex functions on simple polytope, proving existence and uniqueness of optimizer.
result Existence and uniqueness of optimizer for toric non-archimedean μ^λ-entropy for λ ≤ 0.

In \cite{btoric}, Guillemin et al. proved a Delzant-type theorem which classifies bb-symplectic toric manifolds. More generally, in \cite{torus} they proved a similar convexity result for general Hamiltonian torus action on bb-symplectic manifolds. In this paper, we provide a new way to construct bb-symplectic toric…

2019-12-01abs ↗pdf ↗

The paper develops quaternionic toric geometry and classifies local actions.

problem Classifying local quaternionic torus actions on manifolds.
method Develops local QnQ^n-actions, introduces invariants, and studies tetraplectic structures.
result Classifies local quaternionic torus actions up to homeomorphism.

The paper constructs toric vector bundles using spectral networks and non-abelianization.

problem Understanding how holomorphic vector bundles arise from spectral networks and non-abelianization.
method Constructing toric vector bundles on complete toric surfaces via spectral networks and non-abelianization.
result The moduli space of rank 2 toric vector bundles over toric surfaces admits an AA-type X\mathcal{X}-cluster structure.

The geodesic flow of a Riemannian metric on a compact manifold QQ is said to be toric integrable if it is completely integrable and the first integrals of motion generate a homogeneous torus action on the punctured cotangent bundle TQQT^*Q\setminus{Q}. If the geodesic flow is toric integrable, the cosphere bundle admit…

2004-06-10abs ↗pdf ↗

The paper connects fibrations to generalized complex structures in semi-toric geometry.

problem Understanding the relationship between fibrations and generalized complex structures.
method Using moment maps in semi-toric geometry and Gompf--Thurston methods for Lie algebroids.
result Constructs self-crossing stable generalized complex four-manifolds and proves compatibility with connected sums.

Almost toric manifolds form a class of singular Lagrangian fibered symplectic manifolds that is a natural generalization of toric manifolds. Notable examples include the K3 surface, the phase space of the spherical pendulum and rational balls useful for symplectic surgeries. The main result of the paper is a complete c…

2003-12-08abs ↗pdf ↗

The paper studies a generalized Pythagorean theorem on dually flat spaces via toric geometry.

problem Understanding the geometry of dually flat spaces and their toric Kähler manifolds.
method Introducing a dually flat structure and Bregman divergence on the boundary of toric Kähler manifolds.
result A continuity and generalized Pythagorean theorem for the divergence on the boundary.

Study Weinstein structures on toric divisors' complements.

problem Understanding Weinstein structures on toric divisors' complements.
method Define a partially-centered condition on Delzant polytopes, develop an algorithm for Weinstein handlebody diagrams.
result Explicit Weinstein structures for complements of smoothed toric divisors.

In [11] it was proved that, given a compact toric Sasaki manifold of positive basic first Chern class and trivial first Chern class of the contact bundle, one can find a deformed Sasaki structure on which a Sasaki-Einstein metric exists. In the present paper we first prove the uniqueness of such Einstein metrics on com…

2007-01-04abs ↗pdf ↗

This paper introduces the notion of twisted toric manifolds which is a generalization of one of symplectic toric manifolds, and proves the weak Delzant type classification theorem for them. The computation methods for their fundamental groups, cohomology groups in general cases, and signatures in four-dimensional cases…

2006-05-15abs ↗pdf ↗

A principal toric bundle MM is a complex manifold equipped with a free holomorphic action of a compact complex torus TT. Such a manifold is fibered over M/TM/T, with fiber TT. We discuss the notion of positivity in fiber bundles and define positive toric bundles. Given an irreducible complex subvariety XMX\subset M o…

2007-03-06abs ↗pdf ↗

Classification of toric self-dual Einstein gravitational instantons with negative cosmological constant

problem Classification of toric self-dual Einstein gravitational instantons
method Proving that if the conformal Kähler structure associated to one of the torus Killing fields is global and extends to an ALE manifold with no additional fixed points, then the corresponding self-dual Einstein instanton is precisely given by the infinite class of multipole solutions
result The classification of toric self-dual Einstein gravitational instantons is precisely given by the infinite class of multipole solutions

Study of Hermitian structures on toric suspensions of balanced manifolds.

problem Exploring Hermitian structures on specific types of manifolds.
method Analysis of toric suspensions of Calabi-Yau and hyperkähler manifolds under holomorphic automorphisms.
result Suspensions of hyperkähler manifolds do not admit certain Hermitian metrics.

Study of multi-toric geometries with larger compact symmetry groups.

problem Exploring manifolds with special holonomy and toric structures.
method Analyzing manifolds with multi-moment maps and connected non-Abelian symmetry groups.
result Only structures with cohomogeneity-two action of T3imesSU(2)T^{3} imes \mathrm{SU}(2) for Spin(7)\mathrm{Spin}(7)-manifolds.

Study properties of contact structures on symplectic disk bundles with concave boundaries.

problem Understanding the geometric properties of contact structures on concave boundaries of symplectic disk bundles.
method Use tools from toric geometry and algebraic torsion measurements from embedded contact homology.
result All such contact manifolds have a global contact toric structure, and can be tight or overtwisted.

We show a bijective correspondence between compact toric locally conformally symplectic manifolds which admit a compatible complex structure and pairs (C,a)(C,a), where CC is a good cone in the dual Lie algebra of the torus and aa is a positive real number. Moreover, we prove that any toric locally conformally Kähler me…

2019-02-06abs ↗pdf ↗

Plastikstufes and overtwistedness for higher-dimensional contact manifolds are studied in this paper. It is proved that a contact structure is overtwisted if and only if there exists a small plastikstufe with toric core that has trivial rotation.

2016-09-03abs ↗pdf ↗

We give a correspondence between toric 3-Sasaki 7-manifolds S and certain toric Sasaki-Einstein 5-manifolds M. These 5-manifolds are all diffeomorphic to k#(S^2\times S^3), where k=2b_2(S)+1, and are given by a pencil of Sasaki embeddings of M in S and are given concretely by the zero set of a component of the 3-Sasaki…

2006-07-27abs ↗pdf ↗

We classify real Poisson structures on complex toric manifolds of type (1,1)(1,1) and initiate an investigation of their Poisson cohomology. For smooth toric varieties, such structures are necessarily algebraic and are homogeneous quadratic in each of the distinguished holomorphic coordinate charts determined by the open …

2016-10-29abs ↗pdf ↗

We construct globally-defined SU(3)SU(3) structures on smooth compact toric varieties (SCTV) in the class of CP1\mathbb{CP}^1 bundles over MM, where MM is an arbitrary SCTV of complex dimension two. The construction can be extended to the case where the base is Kähler-Einstein of positive curvature, but not necessarily t…

2017-07-14abs ↗pdf ↗

Geometric quantization for specific symplectic structures proved.

problem Quantization of specific symplectic structures.
method Geometric quantization for constant rank presymplectic structures with Riemannian null foliation.
result Quantization-commutes-with-reduction theorem proved in this context.

A theorem of Delzant states that any symplectic manifold $(M,\om)$ of dimension 2n2n, equipped with an effective Hamiltonian action of the standard nn-torus $\T^n = \R^{n}/2π\Z^n$, is a smooth projective toric variety completely determined (as a Hamiltonian $\T^n$-space) by the image of the moment map φ:MRnφ:M\to\R^n, a …

2000-04-19abs ↗pdf ↗