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arXiv research

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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48 results for metric affine gravity

The polynomial affine model of gravity is explored in 3D, focusing on cosmological solutions.

problem Exploring deviations from general relativity in a 3D context.
method Developed a polynomial affine model of gravity, applied to homogeneous isotropic cosmological models, and classified solutions.
result Explicit solutions derived from the connection allow the definition of alternative/emergent metrics.

A classical pp-wave is a 4-dimensional Lorentzian spacetime which admits a nonvanishing parallel spinor field; here the connection is assumed to be Levi-Civita. We generalise this definition to metric compatible spacetimes with torsion and describe basic properties of such spacetimes. We use our generalised pp-waves fo…

2005-05-31abs ↗pdf ↗

A method to derive Lagrangians from field equations in metric-affine theories of gravity.

problem Deriving Lagrangians from field equations in metric-affine theories of gravity.
method Variational completion method to transform field equations into Euler-Lagrange equations and find a Lagrangian.
result Starting from metric equations, full metric equations and Lagrangian can be derived up to metric-independent terms.

Classifies connections on Galilei manifolds, generalizing known results.

problem Classifying general affine connections on Galilei manifolds.
method Classification through tensor fields, extending known Galilei connections.
result Additional freedom in connections not metric-compatible, linked to clock form and space metric.

A common approach to metric-affine, local Poincaré, special-relativistic and Galilei spacetime geometry is developed. Starting from an affine composite bundle, we introduce local reference frames and their evolution along worldlines and we study both, absolute and relative simultaneity postulates, giving rise to altern…

2014-07-30abs ↗pdf ↗

We formulate an approach to the geometry of Riemann-Cartan spaces provided with nonholonomic distributions defined by generic off-diagonal and nonsymmetric metrics inducing effective nonlinear and affine connections. Such geometries can be modelled by moving nonholonomic frames on (pseudo) Riemannian manifolds and desc…

2008-06-24abs ↗pdf ↗

We state and prove a simple Theorem that allows one to generate invariant quantities in Metric-Affine Geometry, under a given transformation of the affine connection. We start by a general functional of the metric and the connection and consider transformations of the affine connection possessing a certain symmetry. We…

2019-11-11abs ↗pdf ↗

The paper explores the connection between 3d gravity and Chern-Simons theory using affine group connections.

problem Exploring the relationship between 3d gravity and Chern-Simons theory.
method A variational problem of Chern-Simons type on a principal fiber bundle with general affine group structure is studied. The connection is established through a generalized notion of extension and reduction of connections.
result Established a correspondence between 3d gravity and Chern-Simons theory using affine group connections.

For (2+2)-dimensional nonholonomic distributions, the physical information contained into a spacetime (pseudo) Riemannian metric can be encoded equivalently into new types of geometric structures and linear connections constructed as nonholonomic deformations of the Levi-Civita connection. Such deformations and induced…

2009-02-05abs ↗pdf ↗

We show that, when considering the anisotropic scaling factors and their derivatives as affine variables, the coefficients of the heat kernel expansion of the Dirac-Laplacian on SU(2)SU(2) Bianchi IX metrics are algebro-geometric periods of motives of complements in affine spaces of unions of quadrics and hyperplanes. We …

2017-09-23abs ↗pdf ↗

Paper presents an action principle for Einstein-Weyl equations in 3D.

problem Finding an action principle for Einstein-Weyl equations.
method Metric affine f(R) gravity action plus additional terms involving Lagrange multipliers and gravitational Chern-Simons contributions.
result The Weyl vector dynamics is governed by a special case of the generalized monopole equation.

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.

By using a projective connection over the space of two-dimensional affine connections, we are able to show that the metric interaction of Polyakov 2D gravity with a coadjoint element arises naturally through the projective Ricci tensor. Through the curvature invariants of Thomas-Whitehead, we are able to define an acti…

2017-12-14abs ↗pdf ↗

By analyzing the affine Taylor expansion of a non-degenerate plane curve, we obtain characterizations of classes of such curves via curvature properties of the gravity curve. The proof is based on an analysis of the degree parity and leading coefficients of polynomials occurring in the expansion.

2011-10-29abs ↗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.

We consider spacetime to be a connected real 4-manifold equipped with a Lorentzian metric and an affine connection. The 10 independent components of the (symmetric) metric tensor and the 64 connection coefficients are the unknowns of our theory. We introduce an action which is quadratic in curvature and study the resul…

2003-04-06abs ↗pdf ↗

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 ↗

One has not any conventional energy-momentum conservation law in Lagrangian field theory, but relations involving different stress-energy-momentum tensors associated with different connections. It is not obvious how to choose the true energy-momentum tensor. This problem is solved in the framework of the multimomentum …

1995-03-22abs ↗pdf ↗

New geometries defined for string models, filling gaps in the literature.

problem Developing mathematical structures for string models.
method Defining E-metric-connection geometries and locality structures.
result Unified framework for metric-affine and generalized geometries.

Length metrics can be closely approximated by conformally flat metrics.

problem Approximating length metrics with conformally flat metrics.
method Uniform approximation of length metrics by conformally flat Riemannian metrics.
result Any length metric on \(\mathbb{R}^d\) can be uniformly approximated by conformally flat Riemannian metrics.

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 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 ↗

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.

Einstein-Kropina metrics extend Einstein condition to all signatures and classify Finsler gravity solutions.

problem Einstein-Kropina metrics in Finsler gravity
method Generalize Einstein condition and classify solutions
result All Einstein-Kropina solutions to the ΛΛ-vacuum equation are Berwald and Ricci-flat, with vanishing cosmological constant.

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 ↗

Perelman's Ricci flow emerges in quantum gravity, linking math and physics.

problem Understanding Perelman's Ricci flow equations in quantum gravity.
method Mapping Perelman's Ricci flow equations to localization equations in topological quantum gravity.
result Perelman's dilaton and fixed volume condition emerge dynamically.

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 'anholonomic frame' method (see gr-qc/0005025, gr-qc/0001060 and hep-th/0110250) is applied for constructing new classes of exact solutions of vacuum Einstein equations with off-diagonal metrics in 4D and 5D gravity. We examine several black tori solutions generated by anholonomic transforms with non-trivial topolo…

2001-10-30abs ↗pdf ↗