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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.

168,695 papers · 148 categories

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1122 · Aug 201919922001200920172026
18 results for non-Ricci-flat

We show that for an nn dimensional complete non Ricci flat gradient steady Ricci soliton with potential function ff bounded above by a constant and curvature tensor RmRm satisfying limrrRm<15\overline{\lim}_{r\to \infty} r|Rm|<\frac{1}{5}, then RmCer|Rm|\leq Ce^{-r} for some constant C>0C>0, improving a result of [36]. For any f…

2019-08-27abs ↗pdf ↗

We introduce a systematic method to produce left-invariant, non-Ricci-flat Einstein metrics of indefinite signature on nice nilpotent Lie groups. On a nice nilpotent Lie group, we give a simple algebraic characterization of non-Ricci-flat left-invariant Einstein metrics in both the class of metrics for which the nice b…

2018-05-22abs ↗pdf ↗

We study the non Ricci flat gradient steady Kähler Ricci soliton with non-negative Ricci curvature and weak integrability condition of the scalar curvature SS, namely limrr1BrS=0\underline{\lim}_{r\to \infty} r^{-1}\int_{B_r} S=0, and show that it is a quotient of Σ×Cn1k×NkΣ\times \mathbb{C}^{n-1-k}\times N^k, where ΣΣ and NN denot…

2019-08-27abs ↗pdf ↗

The configuration space of the reduced Hamiltonian formulation of quantum gravity has been shown, for non-Ricci flat metrics, to be a higher-dimensional analogue of the Teichmüller space of conformal structures on a Riemann surface. In this article we show that the configuration space of conformal connection-dynamics i…

2011-02-27abs ↗pdf ↗

We discuss the mathematical properties of six--dimensional non--Kähler manifolds which occur in the context of N=1{\cal N}=1 supersymmetric heterotic and type IIA string compactifications with non--vanishing background H--field. The intrinsic torsion of the associated SU(3) structures falls into five different classes. …

2002-11-13abs ↗pdf ↗

We study the (2+2)(2+2)-Einstein warped product manifolds, where the scalar curvature of the Base is a multiple of the warping function, and we called this condition (inside a warped product manifold) ff-curvature-Base (RfBR_{f_B}).The aim of this paper is to check if there are Base-manifolds with non-flat metrics that sa…

2019-05-04abs ↗pdf ↗

This paper sets lower bounds for scalar curvatures in Ricci flow singularity models.

problem Understanding scalar curvatures in Ricci flow singularity models.
method Developed high-dimensional theory of Hamilton's Ricci flow, including new monotonicity formulas, compactness theorem, and partial regularity theory.
result Obtained a quadratic decay lower bound for the scalar curvature in 4-dimensional non-Ricci-flat steady soliton singularity models.

We study locally conformal calibrated G2G_2-structures whose underlying Riemannian metric is Einstein, showing that in the compact case the scalar curvature cannot be positive. As a consequence, a compact homogeneous 77-manifold cannot admit an invariant Einstein locally conformal calibrated G2G_2-structure unless the…

2013-03-25abs ↗pdf ↗

In this paper we will show that the generalized connected sum construction for constant scalar curvature metrics can be extended to the zero scalar curvature case. In particular we want to construct solutions to the Yamabe equation on the generalized connected sum M = M_1 (\sharp_K) M_2 of two compact Riemannian manifo…

2006-11-25abs ↗pdf ↗

The paper studies invariant Einstein metrics on Lie supergroups.

problem Investigating invariant Einstein metrics on Lie supergroups.
method Parameterized left invariant metrics, derived Levi-Civita connection and Ricci tensor, reduced Einstein condition to algebraic system.
result Most real basic classical Lie superalgebras admit at least two distinct Einstein metrics.

For even dimensional conformal manifolds several new conformally invariant objects were found recently: invariant differential complexes related to, but distinct from, the de Rham complex (these are elliptic in the case of Riemannian signature); the cohomology spaces of these; conformally stable form spaces that we may…

2007-08-28abs ↗pdf ↗

New exact spherically symmetric vacuum solutions found in Finsler gravity.

problem Finding exact vacuum solutions in Finsler gravity.
method Spherically symmetric, asymptotically flat Berwald spacetimes solved for Finsler gravity vacuum equation.
result Only one class of spherically symmetric Berwald spacetimes is compatible with asymptotic flatness and a well-defined causal structure.

For complete affine manifolds we introduce a definition of compactification based on the projective differential geometry (i.e.\ geodesic path data) of the given connection. The definition of projective compactness involves a real parameter αα called the order of projective compactness. For volume preserving connectio…

2013-04-06abs ↗pdf ↗

The study classifies manifolds based on their geometric properties and invariants.

problem Classifying manifolds based on their geometric and topological properties.
method Analyzing metrics through isometric embeddings and deformations, considering scalar curvature, Ricci tensor, and Einstein metrics.
result The KW type classification of manifolds and sigma invariant calculations.