Tentative Schedule
January 23
Speaker: John McGreevy, MIT
Title: "Holographic Fermi Surfaces and Quantum Electron Stars"
Abstract:
Fermi surfaces are a frontier in our understanding of quantum field
theory. In fact, our understanding of non-Fermi liquids is so poor that
input from string theory (via holographic duality) can be useful. In
this talk, I'll discuss holographic constructions which capture features
of observed non-Fermi liquids, as well as recent progress which
addresses the shortcomings of these constructions.
January 30
Speaker: Jesse Thaler, Massachusetts Institute of Technology
Title: "Goldstini at the LHC"
Abstract:
Supersymmetry is a well-motivated extension of the standard model which offers a rich phenomenology for both collider experiments and dark matter experiments. But if supersymmetry is to be realized in nature, it must be spontaneously broken. To this end, it is conventionally assumed that supersymmetry breaking originates from a single source. In this talk, I will show how the phenomenology of supersymmetry can be dramatically modified if there is more than one source of supersymmetry breaking. In particular, when there are multiple sectors which independently break supersymmetry, there is a corresponding multiplicity of "goldstini", which can have a dramatic impact on collider phenomenology and cosmology. I will discuss a number of interesting goldstini possibilities, including novel stable charged particle studies and invisible Higgs decay modes at the LHC.
February 6
Speaker: Alessandra Buonanno, University of Maryland/Radcliffe
Title: "Advances in Solving the Two-Body Problem in General Relativity: Implications for the Search of Gravitational Waves"
Abstract:
The research at the interface between analytical and numerical
relativity has deepened our understanding of the two-body problem in general relativity, revealing an intriguing simplicity and universality
of the merger signal of coalescing black holes. I will discuss how the
so-called
effective-one-body approach offers a natural explanation for these
results,and explain the importance of accurate modeling for extracting
the best
science upon detection of gravitational waves.
February 13
Speaker: Bob Wald, University of Chicago
Title: "Stability of Black Holes and Black Branes"
Abstract:
I describe recent work with Stefan Hollands (arXiv:1201.0463) that
establishes a close relationship between dynamical stability and
thermodynamic stability for black holes and black branes in classical
general relativity in spacetime dimensions $D \geq 4$. We show that for
axisymmetric perturbations of an arbitrary stationary, axisymmetric
black hole, dynamical stability is equivalent to the positivity of
canonical energy of perturbations that have vanishing linearized ADM
mass and angular momentum at infinity. We further show that positivity
of canonical energy is equivalent to thermodynamic stability. A
thermodynamically unstable black hole may be dynamically stable (as is
the case for a Schwarzschild black hole) if the only perturbations with
negative canonical energy have nonvanishing linearized mass and/or
angular momentum. However, we show that all black branes associated with
thermodynamically unstable black holes must be dynamically unstable, as
conjectured by Gubser and Mitra. We also prove that positivity of
canonical energy for perturbations with vanishing linearized mass and
angular momentum is equivalent to the satisfaction of a "local Penrose
inequality," thus showing that satisfaction of this local Penrose
inequality is necessary and sufficient for dynamical stability.
Although we explicitly consider vacuum general relativity, most of our
results are derived using general Lagrangian and Hamiltonian methods and
therefore can be generalized to allow for the presence of matter fields
and/or to the case of an arbitrary diffeomorphism covariant
gravitational action.
February 20
Speaker: Walter Goldberger, Yale University
Title: "6D methods for 4D superconformal theories"
Abstract:
I will present a manifestly covariant formulation of four-dimensional conformal field theories (CFTs) with N=1 supersymmetry. These methods are a supersymmetric extension of the covariant description of CFTs based on a six-dimensional light cone description of four-dimensional conformal transformations. Applications to Green's functions and to the operator product expansion of superconformal invariant quantum field theory are discussed.
February 27
Speaker: Pavel Fileviez Perez, CCPP, New York University
Title: "The Theory of R-parity and Supersymmetry at the LHC"
Abstract:
The fate of R-parity in the context of the minimal supersymmetric
standard model is a central issue which has profound implications for
particle physics and cosmology. In this talk I discuss the simplest
theory where one can understand the origin of R-parity
(non)conservation. The possible predictions for neutrino physics,
cosmology and the unique signals at the Large Hadron Collider are
discussed in detail.
March 5
Speaker: Frans Pretorius, Princeton University
Title: "Black Holes: Probes of the Cosmos and Fundamental Physics"
Abstract:
The class of spacetimes with event horizons contain some of the most fascinating solutions to the equations of general relativity. Over
the past few years, numerical simulations of the field equations
have begun to reveal some of the more dynamical, strong-field solutions not amenable to exact analytical or perturbative treatments.
In this talk, I will describe 3 such scenarios. First,
the inspiral and merger of two black holes, which is thought to
occur frequently in the universe. Such events are powerful emitters of gravitational waves, and a concerted world-wide effort is currently
underway to observe the universe through gravitational waves.
Second, I will discuss the ultra-relativistic collision of two solitons. Arguments suggest that at sufficiently high velocities
gravity dominates the interaction, causing a black hole
to form regardless of the internal structure or nature of any non-gravitational interaction. These arguments underlie claims
that the Large Hadron Collider will produce black holes in speculative
large extra dimension scenarios. Finally, I will show results elucidating the fate of a black string in 5 dimensions, subject to the Gregory-Laflamme instability. Rather remarkably, the event
horizon exhibits dynamics akin to a low viscosity fluid stream
suffering the Raleigh-Plateau instability, where the horizon starts to form spherical "beads" connected by ever thinner string
segments that are themselves unstable, and the instability unfolds in a self-similar cascade. This process reveals arbitrarily
large spacetime curvatures to an external observer, culminating in naked singularities. This is therefore a generic example
of cosmic censorship violation in higher dimensional Einstein gravity.
April 2
Speaker: David Shih, Rutgers University
Title: "Bounds on SCFTs from Conformal Perturbation Theory"
Abstract:
The operator product expansion (OPE) in 4d
(super)conformal field theory is of broad interest, for both formal and
phenomenological applications. In this talk, I will show how to use conformal
perturbation theory to study the OPE of nearly-free fields coupled to SCFTs.
Under fairly general assumptions, I will show that the OPE of a chiral operator
of dimension \Delta = 1+\epsilon with its complex conjugate always contains an
operator of dimension less than 2 \Delta.
This bound applies to Banks-Zaks fixed points and their generalizations,
as I will illustrate using several examples.
April 16
Speaker: Jonathan Heckman, Institute for Advanced Study
Title: "4D Gravity from a Matrix Model"
Abstract:
In this talk we discuss a proposed dual matrix formulation
of N = 4 Super Yang-Mills on R^4 coupled to 4D Einstein supergravity. We review
the evidence accumulated so far in favor of this proposal, which includes a successful
match of the symmetries of the continuum theory, and the computation of MHV
gluon and graviton scattering amplitudes in terms of matrix model correlators.
We also discuss some avenues of ongoing investigation.
April 23
Speaker: Slava Rychkov, Univ. Paris 6
and Ecole Normale Sup.
Title: "3D Ising Model as a
Conformal Field Theory"
Abstract:
Renormalization group (RG) and Conformal Field Theory (CFT) are two complementary
approaches to the theory of critical
phenomena. The RG explains the underlying physical picture, while CFT has been
very efficient in solving models exactly. Until recently CFT was applied mostly
in 2D, where the conformal group is infinite dimensional. However, it can be
useful also in 3D, as we will explain in this talk.
April 30
Speaker: Raphael Flauger, NYU and IAS Princeton
Title: "Effective Strings
Revisited''
Abstract:
String-like objects arise in many quantum field theories.
Well known examples include flux tubes in QCD and cosmic strings. To a first
approximation, their dynamics is governed by the Nambu-Goto action, but for QCD
flux tubes numerical calculations of the energy levels of these objects have
become so accurate that a systematic understanding of corrections to this
simple description is desirable.
In the first part of my talk, I discuss an effective field
theory describing long relativistic strings. The construction parallels that of
the chiral Lagrangian in that it is based on the pattern of symmetry breaking.
To compare with previous works, I will present the results of the calculation
of the S-matrix describing the scattering of excitations on the string
worldsheet.
In the second part of my talk, I will discuss critical
strings from the same point of view and show that the worldsheet S-matrix in
this case is non-trivial but can be calculated exactly. I will show that it
encodes the familiar square-root formula for the energy levels of the string,
the Hagedorn behavior of strings, and argue that the theory on the string
worldsheet behaves like a 1+1 dimensional theory of quantum gravity rather than
a field theory.
May 29 (TUESDAY)
Speaker: Claudia de Rham, Geneva University
Title: "Massive Gravity in de Sitter"
Abstract:
After reviewing recent
progress in Massive Gravity, I will show how to derive its decoupling limit on
de Sitter. Great care is taken into successfully identifying the proper
helicity-0 mode in that case. I will then explore the partially massless limit
and show that a new Vainshtein mechanism is at work in that limit. I will then
discuss the consequences of partially massless gravity and briefly comment on
the AdS case.
