A5055677812- Black Holes and Theoretical Physics
- Cosmology and Gravitation Theories
- Noncommutative and Quantum Gravity Theories
- Quantum Electrodynamics and Casimir Effect
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Relativity and Gravitational Theory
- Algebraic structures and combinatorial models
- Advanced Differential Geometry Research
- Nonlinear Waves and Solitons
- Quantum and Classical Electrodynamics
- Quantum Chromodynamics and Particle Interactions
- Advanced Mathematical Physics Problems
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Geometric Analysis and Curvature Flows
- Quantum many-body systems
- Galaxies: Formation, Evolution, Phenomena
- High-pressure geophysics and materials
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Particle Accelerators and Free-Electron Lasers
- Advanced Topics in Algebra
- Computational Physics and Python Applications
- Tensor decomposition and applications
University of Massachusetts Amherst
2011-2020
Illinois State University
1999
University of California, Santa Barbara
1999
Imperial College London
1998
Stanford University
1990-1994
University of Chicago
1987-1994
Fermi National Accelerator Laboratory
1987-1994
Queen Mary University of London
1994
Stanford Synchrotron Radiation Lightsource
1991-1993
SLAC National Accelerator Laboratory
1991-1993
We present geometric derivations of the Smarr formula for static AdS black holes and an expanded first law that includes variations in cosmological constant. These two results are further related by a scaling argument based on Euler's theorem. The key new ingredient constructions is two-form potential Killing field. Surface integrals determine coefficient variation constant law. This proportional to finite, effective volume region outside hole horizon, which can also be interpreted as minus...
We consider the thermodynamics of rotating and charged asymptotically de Sitter black holes. Using Hamiltonian perturbation theory techniques, we derive three different first law relations including variations in cosmological constant, associated Smarr formulas that are satisfied by such spacetimes. Each introduces a thermodynamic volume conjugate to constant. examine relation between these volumes geometric number examples, Kerr-dS holes all dimensions Kerr-Newman-dS D=4. also show...
We consider dilaton gravity theories in four spacetime dimensions parametrized by a constant a, which controls the coupling, and construct new exact solutions. first generalize C metric of Einstein-Maxwell theory (a=0) to solutions corresponding oppositely charged black holes undergoing uniform acceleration for general a. next develop solution-generating technique allows us ``embed'' metrics magnetic Melvin backgrounds, thus generalizing Ernst theory. By adjusting parameters appropriately,...
We study properties of static, asymptotically AdS black holes in Lovelock gravity. Our main result is a Smarr formula that gives the mass terms geometrical quantities together with parameters theory. As Einstein gravity, follows from applying first law to an infinitesimal change overall length scale. However, because couplings are dimensionful, we must prove extension includes their variations. Key ingredients this construction Killing-Lovelock potentials associated each higher curvature...
We present simple, analytic solutions to the Einstein-Maxwell equation, which describe an arbitrary number of charged black holes in a spacetime with positive cosmological constant $\ensuremath{\Lambda}$. In limit $\ensuremath{\Lambda}=0$, these reduce well-known Majumdar-Papapetrou (MP) solutions. Like MP solutions, each hole $\ensuremath{\Lambda}>0$ solution has charge $Q$ equal its mass $M$, up possible overall sign. Unlike $\ensuremath{\Lambda}=0$ limit, however, are highly dynamical....
Entanglement entropy in conformal field theories is known to satisfy a first law. For spherical entangling surfaces, this has been shown follow via the AdS/CFT correspondence and holographic prescription for entanglement from bulk law Killing horizons. The can be extended include variations cosmological constant Λ, which we established earlier work. Here show that implies an extension of boundary varying number degrees freedom CFT. thermodynamic potential conjugate Λ called volume simple...
An explicit formula for the ADM mass of an asymptotically AdS black hole in a generic Lovelock gravity theory is presented, identical form to that Einstein gravity, but multiplied by function coupling constants and curvature radius. A Gauss' law-type relates mass, which integral at infinity, expression depending instead on horizon This other thermodynamic quantities, such as free energy, are then analyzed limits small large radius, yielding results independent detailed choice couplings. In...
There exists an upper limit on the mass of black holes when cosmological constant \ensuremath{\Lambda} is positive. We study collision two whose total exceeds this limit. Our investigation based a recently discovered exact solution describing Q=M with \ensuremath{\Lambda}>0. The global structure analyzed. find that if less than extremal limit, then coalesce. If it greater, naked singularity forms to future Cauchy horizon. However, horizon not smooth. Generically, there mild curvature...
New stationary solutions of $4$-dimensional dilaton-axion gravity are presented, which correspond to the charged Taub-NUT and Israel-Wilson-Perjes (IWP) Einstein-Maxwell theory. The axion-dilaton shown have a number interesting properties: i) manifest $SL(2,R)$ symmetry, ii) an infinite throat in extremal limit, iii) limit coincides with exact CFT construction. IWP admit supersymmetric Killing spinors, when embedded $d=4,N=4$ supergravity. This poses problem for interpretation rotating as...
The interplay of black hole and cosmological horizons introduces distinctive thermodynamic behavior for deSitter holes, including well-known upper bounds the mass entropy. We point to a new such feature, Schottky peak in heat capacity Schwarzschild–deSitter (SdS) holes. With this mind, we explore statistical models underlying quantum degrees freedom SdS While simple two-state spin model gives behavior, order capture non-equilibrium nature system consider with large number non-interacting...
It is shown that topologically stable cosmic strings can, in fact, appear to end or break, even theories without monopoles. This can occur whenever the spatial topology of universe nontrivial. For case Abelian-Higgs strings, we describe gauge and scalar field configurations necessary for a string on black hole. We give lower bound rate at which will break via hole pair production, using an instanton calculation based Euclidean C-metric.
The Komar integral relation of Einstein gravity is generalized to Lovelock theories gravity. This includes, in particular, a new boundary for the mass with non-zero cosmological constant, which has finite result asymptotically AdS black holes, without need an infinite background subtraction. Explicit computations are given holes pure gravities all orders and general Gauss–Bonnet theories.
We study evolution and thermodynamics of a slow-roll transition between early late time de Sitter phases, both in the homogeneous case presence black hole, scalar field model with generic potential having maximum positive minimum. Asymptotically future spacetimes are characterized by ADM charges known as cosmological tensions. show that phase has finite tension when oscillation around its minimum is underdamped, while overdamped diverges. compute variation hole horizon areas finding...
We construct a set of conserved charges for asymptotically de Sitter spacetimes that correspond to asymptotic conformal isometries. The are given by boundary integrals at spatial infinity in the flat cosmological slicing Sitter. Using spinor construction, we show charge associated with time translations is necessarily positive and hence may provide useful definition energy these spacetimes. A similar construction shows translation Killing vector static coordinates has both negative definite...
We derive new thermodynamic relations for asymptotically planar AdS black hole and soliton solutions. In addition to the ADM mass, these spacetimes are characterized by gravitational tensions in each of spatial directions. show that with asymptotics, sum mass necessarily vanishes, as one would expect from /CFT correspondence. Each Killing vector such a spacetime leads Smarr formula relating tensions, horizon bubble areas, set volumes arise due non-vanishing cosmological constant. These...
In order to study the properties of Lovelock gravity theories in low dimensions, we define kth-order Riemann-Lovelock tensor as a certain quantity having total 4k-indices, which is kth Riemann curvature and shares its basic algebraic differential properties.We show that determined by traces dimensions 2k ≤ D < 4k.In = + 1 this identity implies all solutions pure are 'Riemann-Lovelock' flat.It verified static, spherically symmetric these theories, missing solid angle space times, indeed...