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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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14274154 · Jun 202019922001200920172026
48 results for modified gravity

The paper introduces and analyzes pseudo generalized Ricci-recurrent spacetimes in modified gravity.

problem Characterizing and analyzing pseudo generalized Ricci-recurrent spacetimes in modified gravity.
method Introducing and characterizing pseudo generalized Ricci-recurrent spacetimes, proving their properties, and studying their impact under modified gravity scenarios.
result Pseudo generalized Ricci-recurrent spacetimes represent specific spacetime types under modified gravity scenarios.

The article introduces pseudo generalized Ricci-recurrent spacetimes and their applications in modified gravity.

problem Characterizing and understanding pseudo generalized Ricci-recurrent spacetimes.
method Introduced and characterized pseudo generalized Ricci-recurrent spacetimes, provided examples, and studied their implications in modified gravity.
result Pseudo generalized Ricci-recurrent spacetimes represent perfect fluid spacetimes and can model dark energy epochs or static spacetimes.

Study on generalized mm-Kropina metrics in modified gravity and cosmology.

problem Understanding the geometric properties and applications of generalized mm-Kropina metrics.
method Proving the rationality of Finslerian geometric objects and studying the conditions for Einstein metrics.
result Conditions for a generalized mm-Kropina metric to be an exact solution in modified gravity and cosmology.

Bayesian neural networks improve cosmic parameter estimation from modified gravity simulations.

problem Estimating cosmological parameters from large-scale structure data with modified gravity.
method Implement Bayesian neural networks (BNNs) with two cases: single BLL and FullB, trained on dark matter only particle mesh NN-body simulations.
result BNNs yield well-calibrated uncertainty estimates and accurately predict cosmological parameters for ΩmΩ_m and σ8σ_8.

The study characterizes spacetime and modified gravity models using projective curvature tensor.

problem Characterizing spacetime and modified gravity models with projective curvature tensor.
method Analyzing $f\left(R,G ight)$, $f\left(R,T ight)$, and $f\left(R,L_{m} ight)$-gravity models.
result Projectively flat perfect fluid spacetimes represent dark energy era and are locally isometric to Minkowski or de-Sitter spacetimes.

Study examines how Lorentz transformations affect foliations in spacetime.

problem Understanding foliations and their relation to observers under Lorentz transformations.
method Exploration of kinematic characteristics of timelike congruences (observers) and their relation to foliations.
result Local Lorentz transformations impact the existence of transversal foliations.

We show that near-horizon geometries in the presence of a positive cosmological constant cannot exist with ring topology. In particular, de Sitter black rings with vanishing surface gravity do not exist. Our result relies on a known mathematical theorem which is a straightforward consequence of a type of energy conditi…

2017-08-11abs ↗pdf ↗

This work presents the foundations of Singular Semi-Riemannian Geometry and Singular General Relativity, based on the author's research. An extension of differential geometry and of Einstein's equation to singularities is reported. Singularities of the form studied here allow a smooth extension of the Einstein field eq…

2013-01-10abs ↗pdf ↗

We present a string inspired 3D Euclidean field theory as the starting point for a modified Ricci flow analysis of the Thurston conjecture. In addition to the metric, the theory contains a dilaton, an antisymmetric tensor field and a Maxwell-Chern Simons field. For constant dilaton, the theory appears to obey a Birkhof…

2003-06-27abs ↗pdf ↗

PhD dissertation on Finsler geometry and gravity, focusing on Berwald spaces and exact solutions.

problem Characterizing and solving Finsler gravity equations.
method Analysis of Berwald spaces, (α,β)(α,β)-metrics, and exact solutions to Finsler gravity equations.
result Exact vacuum solutions in Finsler gravity.

A relation between gravity on Poisson manifolds proposed in arXiv:1508.05706 and Einstein gravity is investigated. The compatibility of the Poisson and Riemann structures defines a unique connection, the contravariant Levi-Civita connection, and leads to the idea of the contravariant gravity. The Einstein-Hilbert-type …

2016-10-20abs ↗pdf ↗

A differential calculus, differential geometry and the E-R Gravity theory are studied on noncommutative spaces. Noncommutativity is formulated in the star product formalism. The basis for the gravity theory is the infinitesimal algebra of diffeomorphisms. Considering the corresponding Hopf algebra we find that the defo…

2006-11-02abs ↗pdf ↗

We argue that Horava-Lifshitz (HL) gravity provides the minimal holographic dual for Lifshitz-type field theories with anisotropic scaling and dynamical exponent z. First we show that Lifshitz spacetimes are vacuum solutions of HL gravity, without need for additional matter. Then we perform holographic renormalization …

2012-11-20abs ↗pdf ↗

We use conformal, but ghostful, Weyl gravity to study its ghost-free, second derivative, partially massless (PM) spin 2 component in presence of Einstein gravity with positive cosmological constant. Specifically, we consider both gravitational- and self- interactions of PM via the fully non-linear factorization of conf…

2012-08-07abs ↗pdf ↗

A theory of gravitation is proposed, modeled after the notion of a Ricci flow. In addition to the metric an independent volume enters as a fundamental geometric structure. Einstein gravity is included as a limiting case. Despite being a scalar-tensor theory the coupling to matter is different from Jordan-Brans-Dicke gr…

2006-02-14abs ↗pdf ↗

We simplify and extend a 6D conformal gravity theory to 8D, linking it to Q-curvature.

problem Constructing and understanding conformal gravity actions in different dimensions.
method Streamlined construction of 6D action, proving existence of 8D action, relating to Q-curvature.
result A unique 8D conformal gravity action exists with Einstein metrics as solutions.

The (2k)(2k)-th Gauss-Bonnet curvature is a generalization to higher dimensions of the (2k)(2k)-dimensional Gauss-Bonnet integrand, it coincides with the usual scalar curvature for k=1k=1. The Gauss-Bonnet curvatures are used in theoretical physics to describe gravity in higher dimensional space times where they are known a…

2007-09-27abs ↗pdf ↗

The study characterizes spacetimes with specific solitons in f(R)f(\mathcal{R})-gravity.

problem Characterizing spacetimes with specific solitons in f(R)f(\mathcal{R})-gravity.
method Analyzing ηη-Ricci solitons, gradient ηη-Ricci solitons, gradient Einstein Solitons, and gradient mm-quasi Einstein solitons in perfect fluid spacetimes obeying f(R)f(\mathcal{R})-gravity.
result Established conditions for the behavior of ηη-Ricci solitons and derived significant theorems about dark matter.

The paper explores generalizations of Mirzakhani's recursion and computes volumes for physical gravity models.

problem Computing volumes for physical gravity models.
method Topological recursion and physical two-dimensional gravity models.
result Derivation of Virasoro constraints and cut-and-join equations for generalized Mirzakhani's recursions.

We show that 3D gravity, in its pure connection formulation, admits a natural 6D interpretation. The 3D field equations for the connection are equivalent to 6D Hitchin equations for the Chern-Simons 3-form in the total space of the principal bundle over the 3-dimensional base. Turning this construction around one gets …

2016-05-24abs ↗pdf ↗

Theory for gravity coupled with fields on manifolds with null-boundary.

problem Formulating a theory for gravity coupled with scalar, SU(n), and spinor fields on manifolds with null-boundary.
method Symplectic reduction of boundary fields and constraints analysis.
result The set of constraints does not form a first class system for the three couplings.

New models predict mobility flows as well as complex machine learning but are simpler and interpretable.

problem Incomplete understanding and modeling of human mobility flows.
method Developed simple machine-learned, closed-form models of mobility.
result These models predict mobility flows more accurately than gravity or complex machine/deep learning models.

We show that holographic renormalization of relativistic gravity in asymptotically Lifshitz spacetimes naturally reproduces the structure of gravity with anisotropic scaling: The holographic counterterms induced near anisotropic infinity take the form of the action for gravity at a Lifshitz point, with the appropriate …

2011-12-23abs ↗pdf ↗

Study on the geometry of Cotton gravity field equations.

problem Analyzing the geometry of Cotton gravity field equations.
method Describes the local structure of spatial Riemannian factors and provides sufficient conditions for reduction to φ\varphi-static perfect fluid space-time.
result Provides sufficient conditions for a C-φ\varphi-PF to reduce to a φ\varphi-SPFST.

This study analyzes a non-orientable spacetime model in 1+1D quantum gravity.

problem Analyzing a non-orientable spacetime model in 1+1D quantum gravity.
method Formulated a Jackiw-Teitelboim gravity toy model on the Möbius band, computed Stiefel-Whitney classes, and analyzed the Dirac operator.
result Half-integer momentum quantization, spectral symmetry, vanishing mod-2 index, and η_D(0) = 0 follow.

In this paper we derive a differential identity for linearized gravity on the Kerr spacetime and more generally on vacuum spacetimes of Petrov type D. We show that a linear combination of second derivatives of the linearized Weyl tensor can be formed into a complex symmetric 2-tensor Mab\mathcal{M}_{ab} which solves the…

2016-01-22abs ↗pdf ↗

We present an introduction to the geometry of higher order vector and co-vector bundles (including higher order generalizations of the Finsler geometry and Kaluza--Klein gravity) and review the basic results on Clifford and spinor structures on spaces with generic local anisotropy modeled by anholonomic frames with ass…

2004-06-28abs ↗pdf ↗