Publications (145)
The slowly rotating near extremal D1-D5 system as a `hot tube'
Oleg Lunin, Samir D. Mathur
The geometry of the D1-D5 system with a small angular momentum j has a long throat ending in a conical defect. We solve the scalar wave equation for low energy quanta in this geome…
Lifting of superconformal descendants in the D1-D5 CFT
Marcel R. R. Hughes, Samir D. Mathur, Madhur Mehta
We consider D1-D5-P states in the untwisted sector of the D1-D5 orbifold CFT where we excite one copy of the seed CFT with a left-moving superconformal descendant. When the theory…
Glueball Spectrum for QCD from AdS Supergravity Duality
Richard C. Brower, Samir D. Mathur, Chung-I Tan
We present the analysis of the complete glueball spectrum for the black hole supergravity dual of in strong coupling limit: . The bosonic fields i…
Second order effect of twist deformation in the D1D5 CFT
Zaq Carson, Shaun Hampton, Samir D. Mathur
Thermalization in the D1D5 CFT should occur via interactions caused by the twist operator, which deforms the theory off its free orbifold point. Earlier studies investigating this…
Is the Polyakov path integral prescription too restrictive?
Samir D. Mathur
In the first quantised description of strings, we integrate over target space co-ordinates and world sheet metrics . Such path integrals give scattering amplitudes…
Microstates at the boundary of AdS
Samir D. Mathur, David Turton
The bound states of the D1D5 brane system have a known gravitational description: flat asymptotics, an anti-de Sitter region, and a 'cap' ending the AdS region. We construct pertur…
Giant Gravitons, BPS bounds and Noncommutativity
Sumit R. Das, Antal Jevicki, Samir D. Mathur
It has been recently suggested that gravitons moving in spacetimes along the blow up into spherical branes whose radius increases with increasing a…
Supersymmetry and Membrane Interactions in M(atrix) Theory
Gilad Lifschytz, Samir D. Mathur
We calculate the potential between various configurations of membranes and gravitons in M(atrix) theory. The computed potentials agree with the short distance potentials between co…
Black Holes and Beyond
Samir D. Mathur
The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects woul…
Rotating deformations of AdS_3\times S^3, the orbifold CFT and strings in the pp-wave limit
Oleg Lunin, Samir D. Mathur
We construct an exact metric which at short distances is the metric of massless particles in 5+1 spacetime (moving along a diameter of the sphere) and is AdS_3\times S^3 at infinit…
Falling into a black hole
Samir D. Mathur
String theory tells us that quantum gravity has a dual description as a field theory (without gravity). We use the field theory dual to ask what happens to an object as it falls in…
Correlations in Hawking radiation and the infall problem
Samir D. Mathur, Christopher J. Plumberg
It is sometimes believed that small quantum gravity effects can encode information as `delicate correlations' in Hawking radiation, thus saving unitarity while maintaining a semicl…
Emission from the D1D5 CFT
Steven G. Avery, Borun D. Chowdhury, Samir D. Mathur
It is believed that the D1D5 brane system is described by an 'orbifold CFT' at a special point in moduli space. We first develop a general formulation relating amplitudes in a d-di…
Constructing "hair" for the three charge hole
Samir D. Mathur, Ashish Saxena, Yogesh K. Srivastava
It has been found that the states of the 2-charge extremal D1-D5 system are given by smooth geometries that have no singularity and no horizon individually, but a `horizon' does ar…
Effect of the twist operator in the D1D5 CFT
Zaq Carson, Shaun Hampton, Samir D. Mathur +1
The D1D5 CFT has been very useful in the study of black holes. The interaction in this theory involves a twist operator, which links together different copies of a free CFT. For th…
Where are the states of a black hole?
Samir D. Mathur
We argue that bound states of branes have a size that is of the same order as the horizon radius of the corresponding black hole. Thus the interior of a black hole is not `empty sp…
The Fuzzball Paradigm
Samir D. Mathur, Madhur Mehta
We describe the puzzles that arise in the quantum theory of black holes, and explain how they are resolved in string theory. We review how the Bekenstein entropy is obtained throug…
The universal thermodynamic properties of Extremely Compact Objects
Samir D. Mathur, Madhur Mehta
An extremely compact object (ECO) is defined as a quantum object without horizon, whose radius is just a small distance outside its Schwarzschild radius. We show that any ECO o…
What is the gravity dual of a chiral primary?
Oleg Lunin, Samir D. Mathur, Ashish Saxena
In the AdS/CFT correspondence a chiral primary is described by a supergravity solution with mass equaling angular momentum. For AdS_3 X S^3 we are led to consider three special fam…
Tachyon condensation and `bounce' in the D1-D5 system
Oleg Lunin, Samir D. Mathur, I. Y. Park +1
We construct supergravity solutions dual to microstates of the D1-D3-D5 system with nonzero B field moduli. Just like the D1-D5 solutions in hep-th/0109154 these solutions are gene…
Are there echoes of gravitational waves?
Bin Guo, Samir D. Mathur
In several approaches to evading the information paradox, the semiclassical black hole is replaced by an Exotic Compact Object (ECO). It has been conjectured that gravitational wav…
Scalar propagator in the pp-wave geometry obtained from AdS_5 X S^5
Samir D. Mathur, Ashish Saxena, Yogesh K. Srivastava
We compute the propagator for massless and massive scalar fields in the metric of the pp-wave. The retarded propagator for the massless field is found to stay confined to the surfa…
Oscillating supertubes and neutral rotating black hole microstates
Samir D. Mathur, David Turton
The construction of neutral black hole microstates is an important problem, with implications for the information paradox. In this paper we conjecture a construction of non-supersy…
Universailty of Low Energy Absorption Cross-sections for Black Holes
Sumit R. Das, Gary Gibbons, Samir D. Mathur
In this paper we compute the low energy absorption cross-section for minimally coupled massles scalars and spin- particles, into a general spherically symmetric black hole in…
One-Loop Transition Amplitudes in the D1D5 CFT
Zaq Carson, Shaun Hampton, Samir D. Mathur
We consider the issue of thermalization in the D1D5 CFT. Thermalization is expected to correspond to the formation of a black hole in the dual gravity theory. We start from the orb…
Folds, Bosonization and non-triviality of the classical limit of 2D string theory
Sumit R. Das, Samir D. Mathur
In the 1-dimensional matrix model one identifies the tachyon field in the asymptotic region with a nonlocal transform of the density of fermions. But there is a problem in relating…
Correlation functions for M^N/S_N orbifolds
Oleg Lunin, Samir D. Mathur
We develop a method for computing correlation functions of twist operators in the bosonic 2-d CFT arising from orbifolds M^N/S_N, where M is an arbitrary manifold. The path integra…
From Black Holes to Pomeron: Tensor Glueball and Pomeron Intercept at Strong Coupling
Richard C. Brower, Samir D. Mathur, Chung-I Tan
We briefly review the approach for strong coupling calculation of glueball masses based on the duality between supergravity and Yang-Mills theory. Earlier work is extended to non-z…
Can the universe be described by a wavefunction?
Samir D. Mathur
Suppose we assume that in gently curved spacetime (a) causality is not violated to leading order (b) the Birkoff theorem holds to leading order and (c) CPT invariance holds. Then w…
Black hole size and phase space volumes
Samir D. Mathur
For extremal black holes the fuzzball conjecture says that the throat of the geometry ends in a quantum `fuzz', instead of being infinite in length with a horizon at the end. For t…
Resolving the black hole causality paradox
Samir D. Mathur
The black hole information paradox is really a combination of two problems: the causality paradox and the entanglement problem. The causality paradox arises because in the semiclas…
Metric of the multiply wound rotating string
Oleg Lunin, Samir D. Mathur
We consider a string wrapped many times around a compact circle in space, and let this string carry a right moving wave which imparts momentum and angular momentum to the string. T…
The quantum structure of black holes
Samir D. Mathur
We give an elementary review of black holes in string theory. We discuss black hole entropy from string microstates and Hawking radiation from these states. We then review the stru…
Fuzzballs and Microstate Geometries: Black-Hole Structure in String Theory
Iosif Bena, Emil J. Martinec, Samir D. Mathur +1
The black-hole information paradox provides one of the sharpest foci for the conflict between quantum mechanics and general relativity and has become the proving-ground of would-be…
The fuzzball proposal for black holes: an elementary review
Samir D. Mathur
We give an elementary review of black holes in string theory. We discuss BPS holes, the microscopic computation of entropy and the `fuzzball' picture of the black hole interior sug…
Hawking Radiation from Four-dimensional Schwarzschild Black Holes in M-theory
Sumit R. Das, Samir D. Mathur, P. Ramadevi
Recently a method has been developed for relating four dimensional Schwarzschild black holes in M-theory to near-extremal black holes in string theory with four charges, using suit…
AdS/CFT duality and the black hole information paradox
Oleg Lunin, Samir D. Mathur
Near-extremal black holes are obtained by exciting the Ramond sector of the D1-D5 CFT, where the ground state is highly degenerate. We find that the dual geometries for these groun…
Emission rates, the Correspondence Principle and the Information Paradox
Samir D. Mathur
When we vary the moduli of a compactification it may become entropically favourable at some point for a state of branes and strings to rearrange itself into a new configuration. We…
Nature abhors a horizon
Per Kraus, Samir D. Mathur
The information paradox can be resolved if we recognize that the wavefunctional in gravity should be considered on the {\it whole} of superspace, the space of possible .…
Snowmass White Paper: Micro- and Macro-Structure of Black Holes
Iosif Bena, Emil J. Martinec, Samir D. Mathur +1
The black-hole information paradox provides a stringent test of would-be theories of quantum gravity. String theory has made significant progress toward a resolution of this parado…
Black Holes Inside and Out 2024: visions for the future of black hole physics
Niayesh Afshordi, Abhay Ashtekar, Enrico Barausse +27
The gravitational physics landscape is evolving rapidly, driven by our ability to study strong-field regions, in particular black holes. Black Holes Inside and Out gathered world e…
Fuzzball geometries and higher derivative corrections for extremal holes
Stefano Giusto, Samir D. Mathur
2-charge D1-D5 microstates are described by geometries which end in `caps' near r=0; these caps reflect infalling quanta back in finite time. We estimate the travel time for 3-char…
Radiation from the non-extremal fuzzball
Borun D. Chowdhury, Samir D. Mathur
The fuzzball proposal says that the information of the black hole state is distributed throughout the interior of the horizon in a `quantum fuzz'. There are special microstates whe…
The information paradox: A pedagogical introduction
Samir D. Mathur
The black hole information paradox is a very poorly understood problem. It is often believed that Hawking's argument is not precisely formulated, and a more careful accounting of n…
Geometry of D1-D5-P bound states
Stefano Giusto, Samir D. Mathur
Supersymmetric solutions of 6-d supergravity (with two translation symmetries) can be written as a hyperkahler base times a 2-D fiber. The subset of these solutions which correspon…
Black hole entropy and the semiclassical approximation
Samir D. Mathur
We compute the entropy of the Hawking radiation for an evaporating black hole, in 1+1 dimensions and in 3+1 dimensions. We investigate the validity of the semiclassical approximati…
A microstate for the 3-charge black ring
Stefano Giusto, Samir D. Mathur, Yogesh K. Srivastava
We start with a 2-charge D1-D5 BPS geometry that has the shape of a ring; this geometry is regular everywhere. In the dual CFT there exists a perturbation that creates one unit of…
Full action of two deformation operators in the D1D5 CFT
Zaq Carson, Shaun Hampton, Samir D. Mathur
We are interested in thermalization in the D1D5 CFT, since this process is expected to be dual to black hole formation. We expect that the lowest order process where thermalization…
Real Time Propagator in the First Quantised Formalism
Samir D. Mathur
We argue that a basic modification must be made to the first quantised formalism of string theory if the physics of `particle creation' is to be correctly described. The analogous…
Interactions involving D-branes
Sumit R. Das, Samir D. Mathur
We investigate some aspects of the spectrum of D-branes and their interactions with closed strings. As argued earlier, a collection of many D-strings behaves, at large dilaton valu…
Dynamical evolution in the D1D5 CFT
Bin Guo, Samir D. Mathur
It is interesting to ask: how does the radial space direction emerge from the CFT in gauge-gravity duality? In this context we resolve a long-standing puzzle with the gravity duals…
Statistical interpretation of Bekenstein entropy for systems with a stretched horizon
Oleg Lunin, Samir D. Mathur
For the 2-charge extremal holes in string theory we show that the Bekenstein entropy obtained from the area of the stretched horizon has a statistical interpretation as a `coarse g…
Correlation functions in the CFT(d)/AdS(d+1) correpondence
Daniel Z. Freedman, Samir D. Mathur, Alec Matusis +1
Conformal techniques are applied to the calculation of integrals on AdS(d+1) space which define correlators of composite operators in the superconformal field theory on the d-dimen…
Contrasting the fuzzball and wormhole paradigms for black holes
Bin Guo, Marcel R. R. Hughes, Samir D. Mathur +1
We examine an interesting set of recent proposals describing a `wormhole paradigm' for black holes. These proposals require that in some effective variables, semiclassical low-ener…
A Note on the Semi-Classical Approximation in Quantum Gravity
Gilad Lifschytz, Samir D. Mathur, Miguel E. Ortiz
We re-examine the semiclassical approximation to quantum gravity in the canonical formulation, focusing on the definition of a quasiclassical state for the gravitational field. It…
The secret structure of the gravitational vacuum
Samir D. Mathur
We argue that the vacuum of quantum gravity must contain a hierarchical structure of correlations spanning all length scales. These correlated domains (called `vecros') correspond…
Non-extremal fuzzballs and ergoregion emission
Borun D. Chowdhury, Samir D. Mathur
In the traditional picture of black holes Hawking radiation is created by pair creation from the vacuum at the horizon. In the fuzzball proposal, individual microstates do not have…
What happens at the horizon?
Samir D. Mathur
The Schwarzschild metric has an apparent singularity at the horizon r=2M. What really happens there? If physics at the horizon is 'normal' laboratory physics, then we run into Hawk…
Comments on black holes I: The possibility of complementarity
Samir D. Mathur, David Turton
We comment on a recent paper of Almheiri, Marolf, Polchinski and Sully who argue against black hole complementarity based on the claim that an infalling observer 'burns' as he appr…
A proposal to resolve the black hole information paradox
Samir D. Mathur
The entropy and information puzzles arising from black holes cannot be resolved if quantum gravity effects remain confined to a microscopic scale. We use concrete computations in n…
Kinetic theory in curved space: a first quantised approach
Samir D. Mathur
We study the real time formalism of non-equilibrium many-body theory, in a first quantised language. We argue that on quantising the relativistic scalar particle in spacetime with…
The information paradox: conflicts and resolutions
Samir D. Mathur
Many relativists have been long convinced that black hole evaporation leads to information loss or remnants. String theorists have however not been too worried about the issue, lar…
The nature of the gravitational vacuum
Samir D. Mathur
The vacuum must contain virtual fluctuations of black hole microstates for each mass . We observe that the expected suppression for is counteracted by the large numbe…
Information Retrieval from a Charge `Trap'
Samir D. Mathur
We study the model of massless electrodynamics with nonconstant coupling, introduced by Peet, Susskind and Thorlacius as the `charge hole'. But we take the boundary of the st…
Absorption of angular momentum by black holes and D-branes
Samir D. Mathur
We consider the absorption of higher angular momentum modes of scalars into black holes, at low energies, and ask if the resulting cross sections are reproduced by a D-brane model.…
Unwinding of strings thrown into a fuzzball
Stefano Giusto, Samir D. Mathur
The traditional black hole has a horizon, with a singularity inside the horizon. But actual microstates of black holes are `fuzzballs', with no horizon and a complex internal struc…
Effective information loss outside the horizon
Samir D. Mathur
If a system falls through a black hole horizon, then its information is lost to an observer at infinity. But we argue that the {\it accessible} information is lost {\it before} the…
Space cannot stretch too {\it fast}
Samir D. Mathur
We argue that black holes microstates leave an imprint on the gravitational vacuum through their virtual fluctuations. This imprint yields a power law fall off -- rather than an ex…
Adding momentum to supersymmetric geometries
Oleg Lunin, Samir D. Mathur, David Turton
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a travelling-wave deformat…
What Exactly is the Information Paradox?
Samir D. Mathur
The black hole information paradox tells us something important about the way quantum mechanics and gravity fit together. In these lectures I try to give a pedagogical review of th…
Black Hole Greybody Factors and Absorption of Scalars by Effective Strings
Igor R. Klebanov, Samir D. Mathur
We compute the greybody factors for classical black holes in a domain where two kinds of charges and their anticharges are excited by the extra energy over extremality. We compare…
A Microscopic Model for the Black hole - Black string Phase Transition
Borun D. Chowdhury, Stefano Giusto, Samir D. Mathur
Computations in general relativity have revealed an interesting phase diagram for the black hole - black string phase transition, with three different black objects present for a r…
What can the information paradox tell us about the early Universe?
Samir D. Mathur
In recent years we have come to understand how the information paradox is resolved in string theory. The huge entropy of black holes is realized by an explici…
Branes wrapping Black Holes
Sumit R. Das, Stefano Giusto, Samir D. Mathur +3
We examine the dynamics of extended branes, carrying lower dimensional brane charges, wrapping black holes and black hole microstates in M and Type II string theory. We show that t…
Discrete Spectrum of the Graviton in the Black Hole Background
Richard C. Brower, Samir D. Mathur, Chung-I Tan
The discrete spectrum of fluctuations of the metric about an black hole background are found. These modes are the strong coupling limit of so called glueball states in a du…
Tensionless strings on orbifolds
Matthias R. Gaberdiel, Bin Guo, Samir D. Mathur
The bound state of one NS5 brane (wrapped on a ) and NS1-branes has two dual descriptions: its low-energy dynamics is described by the symmetric orbifold of $\mat…
Analyzing the squeezed state generated by a twist deformation
Benjamin A. Burrington, Samir D. Mathur, Amanda W. Peet +1
The D1D5 CFT has provided a useful microscopic model for studying black holes. The coupling in this theory is a twist deformation whose action on the vacuum generates a squeezed st…
The magic of the gravitational vacuum
Samir D. Mathur
The black hole information paradox challenges us to do something that is seemingly impossible: find a violation of the semiclassical approximation in a region where all curvatures…
Brane World Gravity in an AdS Black Hole
Richard C. Brower, Samir D. Mathur, Chung-I Tan
We consider a model of brane world gravity in the context of non-conformal non-SUSY matter. In particular we modify the earlier strong coupling solution to the glueball spectrum in…
How fast can a black hole release its information?
Samir D. Mathur
When a shell collapses through its horizon, semiclassical physics suggests that information cannot escape from this horizon. One might hope that nonperturbative quantum gravity eff…
Fuzzballs and black hole thermodynamics
Samir D. Mathur
The fuzzball construction resolves the black hole information paradox by making spacetime end just before the horizon is reached. But if there is no traditional horizon, then do we…
Tunneling into fuzzball states
Samir D. Mathur
String theory suggests that black hole microstates are quantum, horizon sized `fuzzballs', rather than smooth geometries with horizon. Radiation from fuzzballs can carry informatio…
Lifting of states in 2-dimensional supersymmetric CFTs
Bin Guo, Samir D. Mathur
We consider states of the D1-D5 CFT where only the left-moving sector is excited. As we deform away from the orbifold point, some of these states will remain BPS while others can `…
What is the state of the Early Universe?
Samir D. Mathur
As we follow our Universe to early times, we find that matter was crushed to high densities, somewhat similar to the behavior at a black hole singularity. String theory has made pr…
Pair creation in non-extremal fuzzball geometries
Borun D. Chowdhury, Samir D. Mathur
It is possible to construct a special family of nonextremal black hole microstates. These microstates are unstable, and emit radiation at a rate which is found to exactly equal the…
Non-BPS excitations of D-branes and Black holes
Samir D. Mathur
This note discusses some results on the non-BPS excitations of D-branes. We show that the excitation spectrum of a bound state of D-strings changes character when the length of the…
A model with no firewall
Samir D. Mathur
We construct a model which illustrates the conjecture of fuzzball complementarity. In the fuzzball paradigm, the black hole microstates have no interior, and radiate unitarily from…
Universal lifting in the D1-D5 CFT
Bin Guo, Marcel R. R. Hughes, Samir D. Mathur +1
We consider D1-D5-P states in the untwisted sector of the D1-D5 orbifold CFT where one copy of the seed CFT has been excited with a left-moving superconformal primary. Despite bein…
Excitations in the deformed D1D5 CFT
Steven G. Avery, Borun D. Chowdhury, Samir D. Mathur
We perform some simple computations for the first order deformation of the D1D5 CFT off its orbifold point. It had been shown earlier that under this deformation the vacuum state c…
Approaching the surface of an Exotic Compact Object
Shokoufe Faraji, Samir D. Mathur
Many approaches to quantum gravity require replacing the traditional black hole geometry with an Exotic Compact Object (ECO), which has a large but not infinite redshift at its sur…
Gravity on and flat connections in the boundary CFT
Samir D. Mathur
We consider the CFT that arises from the D1-D5 system in the presence of a constant background gauge potential which couples to the R-charge of the theory: this potential effective…
Thermalization in the D1D5 CFT
Shaun Hampton, Samir D. Mathur
It is generally agreed that black hole formation in gravity corresponds to thermalization in the dual CFT. It is sometimes argued that if the CFT evolution shows evidence of large…
Can we observe fuzzballs or firewalls?
Bin Guo, Shaun Hampton, Samir D. Mathur
In the fuzzball paradigm the information paradox is resolved because the black hole is replaced by an object with no horizon. One may therefore ask if observations can distinguish…
Graviton and gauge boson propagators in AdS(d+1)
Eric D'Hoker, Daniel Z. Freedman, Samir D. Mathur +2
We construct the gauge field and graviton propagators in Euclidean AdS(d+1) space-time by two different methods. In the first method the gauge invariant Maxwell or linearized Ricci…
What is the dual of two entangled CFTs?
Samir D. Mathur
It has been conjectured that the dual of the eternal black hole in AdS is two entangled but disconnected CFTs. We show that the entanglement created by the process of Hawking radia…
Membrane paradigm realized?
Samir D. Mathur
Are there any degrees of freedom on the black hole horizon? Using the `membrane paradigm' we can reproduce coarse-grained physics outside the hole by assuming a fictitious membrane…
Black holes and holography
Samir D. Mathur
The idea of holography in gravity arose from the fact that the entropy of black holes is given by their surface area. The holography encountered in gauge/gravity duality has no suc…
Three-point functions for M^N/S^N orbifolds with N=4 supersymmetry
Oleg Lunin, Samir D. Mathur
The D1-D5 system is believed to have an `orbifold point' in its moduli space where its low energy theory is a N=4 supersymmetric sigma model with target space M^N/S^N, where M is T…
Spacetime has a `thickness'
Samir D. Mathur
Suppose we assume that (a) information about a black hole is encoded in its Hawking radiation and (b) causality is not violated to leading order in gently curved spacetime. Then we…
The Operator Product Expansion of N=4 SYM and the 4-point Functions of Supergravity
Eric D'Hoker, Samir D. Mathur, Alec Matusis +1
We give a detailed Operator Product Expansion interpretation of the results for conformal 4-point functions computed from supergravity through the AdS/CFT duality. We show that for…