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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.

168,742 papers · 148 categories

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20406080 · Jun 202019922001200920172026
48 results for quasilocal energy

Motivated by the important work of Brown adn York on quasilocal energy, we propose definitions of quasilocal energy and momentum surface energy of a spacelike 2-surface with positive intrinsic curvature in a spacetime. We show that the quasilocal energy of the boundary of a compact spacelike hypersurface which satisfie…

2003-03-05abs ↗pdf ↗

Paper discusses quasilocal mass and fill-ins, proving positivity and exploring definitions.

problem Exploring and defining quasilocal mass and fill-ins in general relativity.
method Analyzes several proposals of quasilocal mass based on Hamiltonian formulation and proves positivity under certain conditions.
result Positivity of Wang-Yau energy under a more general condition.

Study of quasilocal energy in higher dimensions, focusing on small sphere limits.

problem Understanding quasilocal energy in higher dimensions and its small sphere limits.
method Generalized quasilocal energy definitions, evaluated along lightcone cuts, and compared with known energies.
result The small sphere limits of quasilocal energy in higher dimensions are not proportional to the Bel-Robinson superenergy, challenging its role as gravitational energy.

In general relativity, the local gravitational energy is best characterised by the quasilocal mass. The small sphere limit of quasilocal mass provides us the most local notion of gravitational energy. In four dimensions, the limits were shown be the stress tensor in non-vacuum and the Bel-Robinson tensor in vacuum. We …

2019-09-26abs ↗pdf ↗

We study the limit of quasilocal mass defined in [4] and [5] for a family of spacelike 2-surfaces in spacetime. In particular, we show the limit coincides with the ADM mass at spatial infinity. The limit for coordinate spheres of a boosted slice of the Schwarzchild solution is computed explicitly and shown to give the …

2009-06-01abs ↗pdf ↗

We discuss the concepts of energy and mass in relativity. On a finitely extended spatial region, they lead to the notion of quasilocal energy/mass for the boundary 2-surface in spacetime. A new definition was found in [27] that satisfies the positivity, rigidity, and asymptotics properties. The definition makes use of …

2012-11-06abs ↗pdf ↗

Given a spacelike 2-surface ΣΣ in a spacetime NN and a constant future timelike unit vector T0T_0 in R3,1\R^{3,1}, we derive upper and lower estimates of Wang-Yau quasilocal energy E(Σ,X,T0)E(Σ, X, T_0) for a given isometric embedding XX of ΣΣ into a flat 3-slice in R3,1\R^{3,1}. The quantity E(Σ,X,T0) E(Σ, X, T_0) itself depends …

2009-09-04abs ↗pdf ↗

New definitions of conserved quantities at null infinity resolve ambiguities in general relativity.

problem Ambiguities in defining conserved quantities like angular momentum at null infinity.
method New definitions based on Chen-Wang-Yau quasilocal conserved quantities and optimal isometric embedding theory.
result These new definitions are free of supertranslation ambiguity and limit to classical Bondi mass.

There have been many attempts to define the notion of quasilocal mass for a spacelike 2-surface in spacetime by the Hamilton-Jacobi analysis. The essential difficulty in this approach is to identify the right choice of the background configuration to be subtracted from the physical Hamiltonian. Quasilocal mass should b…

2008-04-08abs ↗pdf ↗

The paper proves a spacetime positive mass theorem for singular initial data sets.

problem Proving the positive mass theorem for initial data sets with corners.
method Extending Hirsch-Kazaras-Khuri's method to singular cases using Hirsch-Miao-Tsang ideas.
result Integral lower bound on spacetime mass and characterisation of zero mass.

New mass definition for negative cosmological constant spacetimes.

problem Defining quasilocal mass for spacetimes with negative cosmological constant.
method Spinorial approach based on previous work for vanishing cosmological constant.
result Non-negative mass, equal to Misner-Sharp mass in spherical symmetry, zero for AdS.

In this note, we compute the limit of the Wang-Yau quasi-local mass on unit spheres at spatial infinity of an asymptotically flat initial data set. Similar to the small sphere limit of the Wang-Yau quasi-local mass, we prove that the leading order term of the quasi-local mass recovers the stress-energy tensor. For a va…

2019-01-21abs ↗pdf ↗

In this paper, we obtain lower bounds for the Brown-York quasilocal mass and the Bartnik quasilocal mass for compact three manifolds with smooth boundaries. As a consequence, we derive sufficient conditions for the existence of horizons for a certain class of compact manifolds with boundary and some asymptotically flat…

2005-11-16abs ↗pdf ↗

New mass inequalities and proofs for causal variational principles.

problem Proving new mass inequalities for causal variational principles.
method Proved a new inequality for minimizers of causal variational principles and applied it to prove the positive mass theorem.
result Introduced a positive quasilocal mass and proved new mass inequalities.

Proposes a new quasi-local mass for timelike 2-surfaces in spacetimes.

problem Need a mass definition for 2-surfaces with timelike mean curvature.
method Adopts Wang-Yau's quasi-local energy framework, modifies for timelike mean curvature.
result Yields a positive definite surface energy density and divergence-free current.

The paper examines mass aspects at future null infinity and limits of quasilocal mass.

problem Understanding mass aspects and limits of quasilocal mass at future null infinity.
method Review and extension of Bondi mass and mass loss formula in Bondi-Sachs coordinate system.
result New results about the limit of quasilocal mass of unit spheres at null infinity.

Study limits of quasi-local angular momentum at infinity of gravitating systems.

problem Understanding limits of quasi-local angular momentum at infinity of gravitating systems.
method Based on optimal isometric embedding and quasilocal mass theory, the study defines and analyzes the limits of quasi-local angular momentum at spatial and null infinity.
result Limits of quasi-local angular momentum are discussed at spatial and null infinity of an isolated gravitating system.

For a spacelike 2-surface in spacetime, we propose a new definition of quasi-local angular momentum and quasi-local center of mass, as an element in the dual space of the Lie algebra of the Lorentz group. Together with previous defined quasi-local energy-momentum, this completes the definition of conserved quantities i…

2013-12-04abs ↗pdf ↗

We study the quasi-local energy (QLE) and the surface geometry for Kerr spacetime in the Boyer-Lindquist coordinates without taking the slow rotation approximation. We also consider in the region r2mr\leq2m, which is inside the ergosphere. For a certain region, r>rk(a)r>r_{k}(a), the Gaussian curvature of the surface with co…

2016-06-27abs ↗pdf ↗

The paper shows how to create Schwarzschild initial data with degenerate apparent horizons.

problem Creating Schwarzschild initial data with degenerate apparent horizons.
method Modifying the construction of Mantoulidis-Schoen to handle the degenerate case.
result The first eigenvalue of the operator LgL_g must be zero for Schwarzschild initial data with degenerate apparent horizons.

We discuss some geometric problems related to the definitions of quasilocal mass proposed by Brown-York \cite{BYmass1} \cite{BYmass2} and Liu-Yau \cite{LY1} \cite{LY2}. Our discussion consists of three parts. In the first part, we propose a new variational problem on compact manifolds with boundary, which is motivated …

2009-06-30abs ↗pdf ↗

We show a uniqueness result for the n-dimensional spatial Reissner-Nordström manifold: a static, electrovacuum, asymptotically flat system which is asymptotically Reissner-Nordström is a subextremal Reissner-Nordström manifold with positive mass, provided that its inner boundary is a (possibly disconnected) photon sphe…

2019-10-23abs ↗pdf ↗

The definition of quasi-local mass for a bounded space-like region in space-time is essential in several major unsettled problems in general relativity. The quasi-local mass is expected to be a type of flux integral on the boundary two-surface and should be independent of whichever space-like region it bounds. An impor…

2008-05-09abs ↗pdf ↗

In this paper we characterize the intrinsic geometry of apparent horizons (outermost marginally outer trapped surfaces) in asymptotically flat spacetimes; that is, the Riemannian metrics on the two sphere which can arise. Furthermore we determine the minimal ADM mass of a spacetime containing such an apparent horizon. …

2014-12-01abs ↗pdf ↗

Optimizes energy efficiency in wireless sensor networks with limited information.

problem Maximizing energy efficiency in energy harvesting wireless sensor networks with limited channel state information.
method Modeling as a Multi-Armed Bandits problem and developing an Upper Confidence Bound algorithm.
result Significant gains in energy efficiency compared to benchmark schemes.

Let EfE_f be the energy of some knot ττ for any ff from certain class of functions. The problem is to find knots with extremal values of energy. We discuss the notion of the locally perturbed knot. The knot circle minimizes some energies EfE_f and maximizes some others. So, is there any energy such that the circle ne…

2004-11-03abs ↗pdf ↗

The paper proves Γ\Gamma-convergence of discrete tangent-point energies to continuous energies and ropelength, with applications to biarc curves.

problem Proving convergence of discrete tangent-point energies to continuous energies and ropelength.
method Using biarc curves and interpolation, the paper proves Γ\Gamma-convergence of discretized tangent-point energies to the continuous tangent-point energies and ropelength functional.
result Discrete almost minimizing biarc curves converge to ropelength minimizers and minimizers of continuous tangent-point energies.

Paper finds relations between Willmore-type energies, weighted areas, and vertical potential energies for cylindrical critical points.

problem Tackles relations between three types of energy functions for cylindrical critical points.
method Uses differential equations and critical point analysis for Willmore-type energies and weighted areas.
result Generating curves coincide for Willmore-type energies and weighted areas, and similar results hold for Willmore-type energies and vertical potential energies.

Quantizes Willmore energy in Riemannian manifolds with bounded energy and area.

problem Quantization of Willmore energy in bounded energy and area conditions.
method Uniform boundedness of Willmore energy and area, weak convergence of maps, and conformal structures in compact domain.
result Quantization of Willmore energy holds under specified conditions.

Enhanced tabular benchmarks for energy-efficient neural architecture search.

problem Energy consumption in deep learning models.
method Introducing EC-NAS, an enhanced tabular benchmark with energy consumption data.
result EC-NAS reveals a balance between energy usage and accuracy in neural architecture search.

Derives energy-momentum tensor from Standard Model, examines energy conditions.

problem Validating energy conditions in the context of the Standard Model.
method Geometric variational problem on globally hyperbolic manifold, deriving energy-momentum tensor.
result Validates various energy conditions in general relativity.