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Articles 1 - 17 of 17
Full-Text Articles in Physics
Chemical Potential In The First Law For Holographic Entanglement Entropy, David Kastor, Sourya Ray, Jennie Traschen
Chemical Potential In The First Law For Holographic Entanglement Entropy, David Kastor, Sourya Ray, Jennie Traschen
David Kastor
Entanglement entropy in conformal field theories is known to satisfy a first law. For spherical entangling surfaces, this has been shown to follow via the AdS/CFT correspondence and the holographic prescription for entanglement entropy from the bulk first law for Killing horizons. The bulk first law can be extended to include variations in the cosmological constant Λ, which we established in earlier work. Here we show that this implies an extension of the boundary first law to include varying the number of degrees of freedom of the boundary CFT. The thermodynamic potential conjugate to Λ in the bulk is called …
Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy, Sebastian Fischetti, David Kastor, Jennie Traschen
Non-Vacuum Ads Cosmologies And The Approach To Equilibrium Of Entanglement Entropy, Sebastian Fischetti, David Kastor, Jennie Traschen
David Kastor
We extend standard results for vacuum asymptotically locally AdS (AlAdS) spacetimes, showing that such spacetimes can be constructed as foliations where the induced metric on each hypersurface satisfies Einstein's equation with stress-energy. By an appropriate choice of stress-energy on the hypersurfaces, the resulting AlAdS spacetime satisfies Einstein's equation with a negative cosmological constant and physical stress tensor. We use this construction to obtain AlAdS solutions whose boundaries are FRW cosmologies sourced by a massless scalar field or by a perfect fluid obeying the strong energy condition. We focus on FRW universes that approach Minkowski spacetime at late times, yielding AlAdS …
Magnetic Fields In An Expanding Universe, David Kastor, Jennie Traschen
Magnetic Fields In An Expanding Universe, David Kastor, Jennie Traschen
David Kastor
We find a solution to 4D Einstein-Maxwell theory coupled to a massless dilaton field describing a Melvin magnetic field in an expanding universe with 'stiff matter' equation of state parameter w=+1. As the universe expands, magnetic flux becomes more concentrated around the symmetry axis for dilaton coupling a<1/3√ and more dispersed for a>1/3√. An electric field circulates around the symmetry axis in the direction determined by Lenz's law. For a=0 the magnetic flux through a disk of fixed comoving radius is proportional to the proper area of the disk. This result disagrees with the usual expectation based on a test magnetic field that this …
Sum Rule For The Adm Mass And Tensions In Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen
Sum Rule For The Adm Mass And Tensions In Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen
David Kastor
An asymptotically planar AdS spacetimes is characterized by its ADM mass and tensions. We define an additional ADM charge Q associated with the scaling Killing vector of AdS, show that Q is given by a certain sum over the ADM mass and tensions and that Q vanishes on solutions to the Einstein equation with negative cosmological constant. The sum rule for the mass and tensions thus established corresponds in an AdS/CFT context to the vanishing of the trace of the boundary stress tensor. We also show that an analogous sum rule holds for local planar sources of stress-energy sources in …
Conformal Tensors Via Lovelock Gravity, David Kastor
Conformal Tensors Via Lovelock Gravity, David Kastor
David Kastor
Constructs from conformal geometry are important in low dimensional gravity models, while in higher dimensions the higher curvature interactions of Lovelock gravity are similarly prominent. Considering conformal invariance in the context of Lovelock gravity leads to natural, higher-curvature generalizations of the Weyl, Schouten, Cotton and Bach tensors, with properties that straightforwardly extend those of their familiar counterparts. As a first application, we introduce a new set of conformally invariant gravity theories in D=4k dimensions, based on the squares of the higher curvature Weyl tensors.
On The Universality Of Inner Black Hole Mechanics And Higher Curvature Gravity, Alejandra Castro, Nima Dehmami, Gaston Giribet, David Kastor
On The Universality Of Inner Black Hole Mechanics And Higher Curvature Gravity, Alejandra Castro, Nima Dehmami, Gaston Giribet, David Kastor
David Kastor
Black holes are famous for their universal behavior. New thermodynamic relations have been found recently for the product of gravitational entropies over all the horizons of a given stationary black hole. This product has been found to be independent of the mass for all such solutions of Einstein-Maxwell theory in d=4,5. We study the universality of this mass independence by introducing a number of possible higher curvature corrections to the gravitational action. We consider finite temperature black holes with both asymptotically flat and (A)dS boundary conditions. Although we find examples for which mass independence of the horizon entropy product continues …
Gravitational Tension And Thermodynamics Of Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen
Gravitational Tension And Thermodynamics Of Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen
David Kastor
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 the planar spatial directions. We show that with planar AdS asymptotics, the sum of the ADM mass and tensions necessarily vanishes, as one would expect from the AdS /CFT correspondence. Each Killing vector of such a spacetime leads to a Smarr formula relating the ADM mass and tensions, the black hole horizon and soliton bubble areas, and a set of thermodynamic volumes that arise due to the non-vanishing cosmological constant. …
Thermodynamic Volumes And Isoperimetric Inequalities For De Sitter Black Holes, Brian P. Dolan, David Kastor, David KubiznˇA´K, Robert B. Mann, Jennie Traschen
Thermodynamic Volumes And Isoperimetric Inequalities For De Sitter Black Holes, Brian P. Dolan, David Kastor, David KubiznˇA´K, Robert B. Mann, Jennie Traschen
David Kastor
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 the cosmological constant, and associated Smarr formulas that are satisfied by such spacetimes. Each first law introduces a different thermodynamic volume conjugate to the cosmological constant. We examine the relation between these thermodynamic volumes and associated geometric volumes in a number of examples, including Kerr-dS black holes in all dimensions and Kerr-Newman-dS black holes in D=4. We also show that the Chong-Cvetic-Lu-Pope solution of D=5 minimal supergravity, analytically continued to positive cosmological …
Angular Tension Of Black Holes, David Kastor, Jennie Traschen
Angular Tension Of Black Holes, David Kastor, Jennie Traschen
David Kastor
Angular tension is an Arnowitt-Deser-Misner charge that contributes a work term to the first law of black hole mechanics when the range of an angular coordinate is varied and leads to a new Smarr formula for stationary black holes. A phase diagram for singly spinning D=5 black holes shows that angular tension resolves the degeneracies between spherical black holes and (dipole) black rings and captures the physics of the black ring balance condition. Angular tension depends on the behavior of the metric at rotational axes and we speculate on its relation to rod/domain structure characterizations of higher-dimensional black holes and …
The Riemann-Lovelock Curvature Tensor, David Kastor
The Riemann-Lovelock Curvature Tensor, David Kastor
David Kastor
In order to study the properties of Lovelock gravity theories in low dimensions, we define the kth-order Riemann-Lovelock tensor as a certain quantity having a total 4k-indices, which is kth-order in the Riemann curvature tensor and shares its basic algebraic and differential properties. We show that the kth-order Riemann-Lovelock tensor is determined by its traces in dimensions 2k \le D <4k. In D=2k+1 this identity implies that all solutions of pure kth-order Lovelock gravity are `Riemann-Lovelock' flat. It is verified that the static, spherically symmetric solutions of these theories, which are missing solid angle space times, indeed satisfy this flatness property. This generalizes results from Einstein gravity in D=3, which corresponds to the k=1 case. We speculate about some possible further consequences of Riemann-Lovelock curvature.
Dynamics Of Localized Kaluza-Klein Black Holes In A Collapsing Universe, David Kastor, Lorenzo Sorbo, Jennie Traschen
Dynamics Of Localized Kaluza-Klein Black Holes In A Collapsing Universe, David Kastor, Lorenzo Sorbo, Jennie Traschen
David Kastor
The Clayton Antitrust Act of 1914 prohibits corporate mergers that would result in certain highly undesired end states. We study an exact solution of the Einstein equations describing localized, charged Kaluza-Klein black holes in a collapsing deSitter universe and seek to demonstrate that a similar effect holds, preventing a potentially catastrophic black hole merger. As the collapse proceeds, it is natural to expect that the black hole undergoes a topological transition, wrapping around the shrinking compact dimension to merge with itself and form a black string. However, the putative uniform charged black string end state is singular and such a …
Mass And Free Energy Of Lovelock Black Holes, David Kastor, Sourya Ray, Jennie Traschen
Mass And Free Energy Of Lovelock Black Holes, David Kastor, Sourya Ray, Jennie Traschen
David Kastor
An explicit formula for the ADM mass of an asymptotically AdS black hole in a generic Lovelock gravity theory is presented, identical in form to that in Einstein gravity, but multiplied by a function of the Lovelock coupling constants and the AdS curvature radius. A Gauss' law type formula relates the mass, which is an integral at infinity, to an expression depending instead on the horizon radius. This and other thermodynamic quantities, such as the free energy, are then analyzed in the limits of small and large horizon radius, yielding results that are independent of the detailed choice of Lovelock …
Kerr-Schild Ansatz In Lovelock Gravity, David Kastor, Benjamin Ett
Kerr-Schild Ansatz In Lovelock Gravity, David Kastor, Benjamin Ett
David Kastor
We analyze the field equations of Lovelock gravity for the Kerr-Schild metric ansatz, gab = g ̄ab + λkakb, with background metric g ̄ab, background null vector ka and free parameter λ. Focusing initially on the Gauss-Bonnet case, we find a simple extension of the Einstein gravity results only in theories having a unique constant curvature vacuum. The field equations then reduce to a single equation at order λ^2. More general Gauss-Bonnet theories having two distinct vacua yield a pair of equations, at orders λ and λ^2 that are not obviously compatible. Our results for higher order Lovelock theories are …
Do Killing-Yano Tensors Form A Lie Algebra?, David Kastor, Sourya Ray, Jenny Traschen
Do Killing-Yano Tensors Form A Lie Algebra?, David Kastor, Sourya Ray, Jenny Traschen
David Kastor
Killing-Yano tensors are natural generalizations of Killing vectors. We investigate whether Killing-Yano tensors form a graded Lie algebra with respect to the Schouten-Nijenhuis bracket. We find that this proposition does not hold in general, but that it does hold for constant curvature spacetimes. We also show that Minkowski and (anti)-deSitter spacetimes have the maximal number of Killing-Yano tensors of each rank and that the algebras of these tensors under the SN bracket are relatively simple extensions of the Poincare and (A)dS symmetry algebras.
Dynamics Of The Dbi Spike Soliton, David Kastor, Jennie Traschen
Dynamics Of The Dbi Spike Soliton, David Kastor, Jennie Traschen
David Kastor
We compare oscillations of a fundamental string ending on a D3-brane in two different settings: (1) a test-string radially threading the horizon of an extremal black D3-brane and (2) the spike soliton of the DBI effective action for a D3-brane. Previous work has shown that overall transverse modes of the test-string appear as l=0 modes of the transverse scalar fields of the DBI system. We identify DBI world-volume degrees of freedom that have dynamics matching those of the test-string relative transverse modes. We show that there is a map, resembling T-duality, between relative and overall transverse modes for the test-string …
Dynamics Of The Dirac-Born-Infeld Spike Soliton, David Kastor, Jennie Traschen
Dynamics Of The Dirac-Born-Infeld Spike Soliton, David Kastor, Jennie Traschen
David Kastor
We compare oscillations of a fundamental string ending on a D3-brane in two different settings: (1) a test string radially threading the horizon of an extremal black D3-brane and (2) the spike soliton of the DBI effective action for a D3-brane. Previous work has shown that overall transverse modes of the test string appear as l=0 modes of the transverse scalar fields of the DBI system. We identify DBI world-volume degrees of freedom that have dynamics matching those of the test-string relative transverse modes. We show that there is a map, resembling T duality, between relative and overall transverse modes …
U-Duality, D-Branes And Black Hole Emission Rates: Agreements And Disagreements, Fay Dowker, David Kastor, Jennie Traschen
U-Duality, D-Branes And Black Hole Emission Rates: Agreements And Disagreements, Fay Dowker, David Kastor, Jennie Traschen
David Kastor
An expression for the spacetime absorption coefficient of a scalar field in a five dimensional, near extremal black hole background is derived, which has the same form as that presented by Maldacena and Strominger, but is valid over a larger, U-duality invariant region of parameter space and in general disagrees with the corresponding D-brane result. We develop an argument, based on D-brane thermodynamics, which specifies the range of parameters over which agreement should be expected. For neutral emission, the spacetime and D-brane results agree over this range. However, for charged emission, we find disagreement in the `Fat Black Hole' regime, …