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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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21426384 · Jun 202019922001200920172026
48 results for AdS spacetimes

The spacetime AdS2×S2AdS_2 \times S^2 is well known to arise as the 'near horizon' geometry of the extremal Reissner-Nordstrom solution, and for that reason it has been studied in connection with the AdS/CFT correspondence. Here we consider asymptotically AdS2×S2AdS_2 \times S^2 spacetimes that obey the null energy condition (or…

2018-03-28abs ↗pdf ↗

We study global aspects of complete, non-singular asymptotically locally AdS spacetimes solving the vacuum Einstein equations whose conformal infinity is an arbitrary globally stationary spacetime. It is proved that any such solution which is asymptotically stationary to the past and future is itself globally stationar…

2006-05-31abs ↗pdf ↗

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.

Unique AdS spacetime found with prescribed metric on a convex surface.

problem Finding an AdS spacetime with a specific metric on a convex surface.
method Constructing a quasifuchsian AdS spacetime with a past-convex Cauchy surface.
result Existence and uniqueness of a quasifuchsian AdS spacetime with the specified properties.

The paper proves a rigidity theorem for null geodesic travel times in asymptotically AdS spacetimes.

problem Determining if a spacetime is conformally AdS based on null geodesic travel times.
method Analyzing all null geodesics from a point to its antipodal point, considering various spacetime conditions.
result The spacetime is conformally AdS if and only if all null geodesics from a point refocus at its antipodal point.

The paper extends spacetime topology results using codimension 2 null cut locus properties.

problem Understanding spacetime topology with and without horizons.
method Review and extension of existing literature on spacetime topology, utilizing codimension 2 null cut locus properties.
result Results for spacetimes with and without horizons, including asymptotically AdS settings.

We derive necessary conditions for the spinorial Witten-Nester energy to be well-defined for asymptotically locally AdS spacetimes. We find that the conformal boundary should admit a spinor satisfying certain differential conditions and in odd dimensions the boundary metric should be conformally Einstein. We show that …

2005-06-15abs ↗pdf ↗

We study the space of Killing fields on the four dimensional AdS spacetime AdS3,1AdS^{3,1}. Two subsets S\mathcal{S} and O\mathcal{O} are identified: S\mathcal{S} (the spinor Killing fields) is constructed from imaginary Killing spinors, and O\mathcal{O} (the observer Killing fields) consists of all hypersurface orthog…

2015-09-30abs ↗pdf ↗

Researchers use conformal infinity to study spacetimes near AdS2×S2.

problem Studying the rigidity of asymptotically AdS2×S2 spacetimes.
method Developed a new approach based on conformal infinity.
result Obtained new results including similar to [4] but for higher dimensions and more than two ends.

In this paper we classify, up to orbit equivalence, cohomogeneity one actions of connected closed Lie subgroups of U(1,n)U(1,n) on the (2n+1)(2n+1)-dimensional anti de Sitter spacetime AdS2n+1AdS^{2n+1}. We also give some new examples of nonproper cohomogeneity one actions on AdSn+1AdS^{n+1} and determine parabolic Lie subgroups of $SO…

2016-09-19abs ↗pdf ↗

We formulate the variational problem for AdS gravity with Dirichlet boundary conditions and demonstrate that the covariant counterterms are necessary to make the variational problem well-posed. The holographic charges associated with asymptotic symmetries are then rederived via Noether's theorem and `covariant phase sp…

2005-05-23abs ↗pdf ↗

We generalize Penrose's notion of conformal infinity of spacetime, to situations with anisotropic scaling. This is relevant not only for Lifshitz-type anisotropic gravity models, but also in standard general relativity and string theory, for spacetimes exhibiting a natural asymptotic anisotropy. Examples include the Li…

2009-09-21abs ↗pdf ↗

The aim of this survey is to give an overview on the geometry of Einstein maximal globally hyperbolic 2+1 spacetimes of arbitrary curvature, conatining a complete Cauchy surface of finite type. In particular a specialization to the finite type case of the canonicla Wick rotation-rescaling theory, previously developed b…

2007-04-17abs ↗pdf ↗

Motivated by recent proposals for a de Sitter version of the AdS/CFT correspondence, we give some topological restrictions on spacetimes of de Sitter type, i.e., spacetimes with Λ>0Λ>0, which admit a regular past and/or future conformal boundary. For example we show that if Mn+1M^{n+1}, n2n \ge 2, is a globally hyperbolic…

2002-02-25abs ↗pdf ↗

The stability of physical systems depends on the existence of a state of least energy. In gravity, this is guaranteed by the positive energy theorem. For topological reasons this fails for nonsupersymmetric Kaluza-Klein compactifications, which can decay to arbitrarily negative energy. For related reasons, this also fa…

2001-08-22abs ↗pdf ↗

Research proves unique continuation for Einstein-vacuum equations on aAdS spacetimes.

problem Establishing rigorous mathematical statements for AdS/CFT correspondence.
method Novel Carleman estimates and unique continuation results for wave equations on aAdS spacetimes.
result Proved a unique continuation result for the Einstein-vacuum equations from aAdS conformal boundaries.

The notion of a causal boundary for a spacetime has been a controversial topic during the last three decades. Moreover, recently the role of the boundary in the AdS/CFT correspondence for plane waves, have stimulated its redefinition with some possible alternatives. Our aim is threefold. First, to review the different …

2008-12-01abs ↗pdf ↗

We study the causality relation in the 3-dimensional anti-de Sitter space AdS and its conformal boundary Ein. To any closed achronal subset ΛΛ in Ein_2{Ein}\_2 we associate the invisible domain E(Λ)E(Λ) from ΛΛ in AdS. We show that if ΓΓ is a torsion-free discrete group of isometries of AdS preserving ΛΛ and is non-elem…

2005-09-23abs ↗pdf ↗

The paper characterizes spin initial data sets saturating the BPS bound in asymptotically AdS spacetimes.

problem Characterizing spin initial data sets saturating the BPS bound in asymptotically AdS spacetimes.
method The paper introduces a theorem for replacing imaginary Killing spinors with strictly timelike or null ones and uses spinors to construct a codimension-2 slicing.
result The paper establishes a sharp dimension threshold for saturating the BPS bound in gravitational waves and rotating black holes in higher dimensions.

No time-periodic Majorana fermions found in Kerr-Newman spacetimes with nontrivial charge.

problem Existence of Majorana fermions in Kerr-Newman spacetimes with nontrivial charge.
method Analysis of Dirac equation in Kerr-Newman spacetimes, leading to algebraic identities.
result No differentiable time-periodic Majorana fermions in Kerr-Newman spacetimes with nontrivial charge.

Proves Penrose inequality for cohomogeneity one initial data sets.

problem Proving Penrose inequality for specific initial data sets.
method Analyzing asymptotically flat and hyperbolic initial data sets under cohomogeneity one actions.
result Total mass is bounded below by a function of outermost apparent horizon area, with equality for Schwarzschild(-AdS) embeddings.

Researchers create holographic super-embeddings for M5 and M2 branes.

problem No concrete examples of super-embeddings for M5 and M2 branes existed.
method Constructed explicit holographic super-embeddings of probe M5 and M2 branes into their super-AdS backgrounds.
result Explicit holographic super-embeddings of M5 and M2 branes were successfully constructed.

We show that Wang's proof of uniqueness of Anti-de Sitter spacetime can be adapted to provide uniqueness results for strictly static asymptotically locally hyperbolic vacuum metrics with toroidal infinity, and to prove negativity of the free energy ETSE-TS of asymptotically AdS black holes with higher-genus horizons.

2019-09-30abs ↗pdf ↗

This article considers the quasi-local conserved quantities with respect to a reference spacetime with a cosmological constant. We follow the approach developed by the authors in [25,26,7] and define the quasi-local energy as differences of surface Hamiltonians. The ground state for the gravitational energy is taken to…

2016-03-09abs ↗pdf ↗

The massive wave equation gψαΛ3ψ=0\Box_g ψ- α\fracΛ{3} ψ= 0 is studied on a fixed Kerr-anti de Sitter background (M,gM,a,Λ)(\mathcal{M},g_{M,a,Λ}). We first prove that in the Schwarzschild case (a=0), ψψ remains uniformly bounded on the black hole exterior provided that α<9/4α< {9/4}, i.e. the Breitenlohner-Freedman bound holds. Our p…

2009-02-05abs ↗pdf ↗

Departing from the observation that the Penrose limit of AdS_3 x S^3 is a group contraction in the sense of Inonu and Wigner, we explore the relation between the symmetric D-branes of AdS_3 x S^3 and those of its Penrose limit, a six-dimensional symmetric plane wave analogous to the four-dimensional Nappi--Witten space…

2003-03-25abs ↗pdf ↗

This paper is the continuation of [8]. We essentially prove that the familly of strongly causal spacetimes defined in [8] associated to generic achronal subsets in Ein contains all the examples of BTZ multi black-holes. It provides new elements for the global description of these multi black-holes. We also prove that a…

2005-10-04abs ↗pdf ↗

A key open problem in M-theory is the identification of the degrees of freedom that are expected to be hidden at ADE-singularities in spacetime. Comparison with the classification of D-branes by K-theory suggests that the answer must come from the right choice of generalized cohomology theory for M-branes. Here we show…

2018-05-15abs ↗pdf ↗

We reinterpret special relativity, or more precisely its de Sitter deformation, in terms of 3d conformal geometry, as opposed to (3+1)d spacetime geometry. An inertial observer, usually described by a geodesic in spacetime, becomes instead a choice of ways to reverse the conformal compactification of a Euclidean vector…

2013-05-14abs ↗pdf ↗