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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.

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48 results for Cotton gravity

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.

We consider instanton solutions of Euclidean Horava-Lifshitz gravity in four dimensions satisfying the detailed balance condition. They are described by geometric flows in three dimensions driven by certain combinations of the Cotton and Ricci tensors as well as the cosmological-constant term. The deformation curvature…

2010-01-30abs ↗pdf ↗

Left-invariant Cotton solitons on homogeneous manifolds are determined. Moreover, algebraic Cotton solitons are studied providing examples of non-invariant Cotton solitons, both in the Riemannian and Lorentzian homogeneous settings.

2013-03-15abs ↗pdf ↗

The paper studies Cotton solitons on specific geometric manifolds.

problem Analyzing Cotton solitons in almost Kenmotsu 3-hh-manifolds.
method Examined potential vector fields and their relationship with the Reeb vector field.
result Steady Cotton solitons on non-Kenmotsu manifolds are locally isometric to H2(4)imesR\mathbb{H}^2(-4) imes \mathbb{R}.

Using the conformally invariant Cotton tensor, we define a geometric flow, the "Cotton flow", which is exclusive to three dimensions. This flow tends to evolve the initial metrics into conformally flat ones, and is somewhat orthogonal to the Yamabe flow, the latter being a flow within a conformal class. We define an en…

2008-03-11abs ↗pdf ↗

We compute the evolution equation of the Cotton and the Bach tensor under the Ricci flow of a Riemannian manifold, with particular attention to the three dimensional case, and we discuss some applications.

2012-03-20abs ↗pdf ↗

This paper classifies solitons under specific tensor conditions.

problem Classifying solitons under vanishing conditions on the Weyl, Cotton, and Cao-Chen tensors.
method Analyzing complete conformal gradient solitons and using tensor conditions.
result Classification of complete nontrivial locally conformally flat conformal gradient solitons.

This paper presents conformal invariants for Riemannian manifolds of dimension greater than or equal to four whose vanishing is necessary for a Riemannian manifold to be conformally related to an Einstein space. One of the invariants is a modification of the Cotton tensor, the other is a nn--dimensional version of the…

2004-08-17abs ↗pdf ↗

The holographic duality can be extended to include quantum theories with broken coordinate invariance leading to the appearance of the gravitational anomalies. On the gravity side one adds the gravitational Chern-Simons term to the bulk action which gauge invariance is only up to the boundary terms. We analyze in detai…

2005-12-18abs ↗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 ↗

New methods incorporate alpha signals into portfolio construction, improving performance.

problem Signal-blindness in existing portfolio construction methods.
method Introduces three methods: HRP-μ\mu, HRP-Σμ\Sigma\mu, and CRISP.
result CRISP at intermediate γ\gamma consistently outperforms other methods.

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 paper classifies electrovacuum spaces in higher dimensions, proving several key results.

problem Classifying regular static black hole solutions of the static Einstein-Maxwell equations.
method Analytical proofs and geometric analysis of electrovacuum spaces.
result An n-dimensional locally conformally flat extremal electrovacuum space must be in the Majumdar-Papapetrou class.

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 ↗

In this article we introduce local gauge conditions under which many curvature tensors appearing in conformal geometry, such as the Weyl, Cotton, Bach, and Fefferman-Graham obstruction tensors, become elliptic operators. The gauge conditions amount to fixing an nn-harmonic coordinate system and normalizing the determi…

2013-10-14abs ↗pdf ↗

We solve the classifying problem raised by Fischer and Marsden for Bach flat static spaces. We also prove the conjecture about critical point equations proposed by Besse for Bach flat manifolds. Particularly in dimension 3, we derive an integral identity that allows us to obtain conformal flatness from the vanish of th…

2012-12-06abs ↗pdf ↗