Archana Anandakrishnan (OSU): "y-Unified GUTS: MSSM at Large tanb" | Jan 15
I will talk about the consequences of gauge and third family Yukawa coupling unification for the LHC. In a recent work, we analyzed a Yukawa unified supersymmetric grand unified theory (GUT) with non-universal Higgs masses defined at the GUT scale. We performed a global fit using 11 observables, including the Higgs boson mass (arXiv:1212.0542). Gluinos should be visible at the LHC in the 14 TeV run but they cannot be described by the typical simplified models (arXiv1307.7723). I will also describe a complete three family model and discuss the quality of the global chi^2 fit to 35 observables. In addition, I will discuss work with a new set of boundary conditions that is consistent with Yukawa unification at the GUT scale (arXiv:1303.5125) and the viability of dark matter in these models (arXiv:1310.7579).
Benjamin Niehoff (USC): "Progress in Black Hole Microstate Geometries" | Jan 22
I will talk about recent progress in microstate geometries toward leaving the BPS limit and matching the entropy scaling of a 3-charge black hole in 5 dimensions.
Felix Yu (FNAL): "Exploring Exotic Production of the 126 GeV Higgs" | Jan 29
I consider the effects of exotic production modes of the 125 GeV Higgs and their impact on Higgs searches and the Higgs discovery. I emphasize that new production modes have been largely overlooked in contemporary tests of the Standard Model nature of the Higgs boson but experimental tests of exotic production modes are viable now or will be soon. I present a couple explicit examples of exotic production arising from chargino-neutralino associated production in the MSSM. As a corollary of this work, I point out that current Higgs coupling fits do not adequately explore the complete space of new physics deviations possible in Higgs measurements.
Vasily Pestun (IAS): "Quantum geometry and quiver gauge theories" | Feb 5
I will explain the relation between certain class of N=2 supersymmetric quiver gauge theories in four dimensions and class of quantum integrable systems whose underlying symmetries are described by quantum algebras such as a Yangian or quantum affine algebra. (Based on arxiv:1312.6689 with N.Nekrasov and S. Shatashvili)
Cora Dvorkin (IAS): "Probing Dark Matter with the Cosmic Microwave Background and Large-Scale Structure" | Feb 12
Cosmological observations and galaxy dynamics seem to imply that five out of six parts in mass of all matter in the Universe is composed of dark matter, that is not accounted for by the Standard Model of particles. The particle nature of dark matter is one of the most intriguing puzzles of our time. It is therefore important to identify astrophysical and cosmological processes where the particle interactions of dark matter may be of relevance.
In this talk, I will show that dark matter annihilation around the time of recombination can lead to growing ionization perturbations that track the linear collapse of matter overdensities. This amplifies small scale cosmological perturbations to the free electron density by a significant amount compared to the usual acoustic oscillations. Electron density perturbations distort the Cosmic Microwave Background (CMB), inducing secondary non-gaussianity.
I will present a novel analytic calculation of CMB non-gaussianity from recombination, providing a clear identification of the relevant physical processes.
In the last part of the talk, I will consider the possibility of dark matter-baryon interactions. I will present results from a Markov Chain Monte Carlo likelihood analysis of CMB data from the Planck satellite and measurements of the Lyman-alpha forest from the Sloan Digital Sky Survey that probe the imprints of these interactions both at large and small scales.
Sungjay Lee (Chicago): "New Exact Results in Calabi-Yau, D-branes, and Orientifold" | Feb 19
We compute the two-sphere, disk and real projective plane partition functions of two-dimensional supersymmetric theories exactly using the localization technique. From these new results, we will attack old and new important problems in the string theory on Calabi-Yau spaces, and D-branes and Orientifold planes therein.
James Unwin (Notre Dame): "Annihilation signals from Asymmetric Dark Matter" | Feb 26
I will begin with an overview of models of Asymmetric Dark Matter, in which the present day density of dark matter (DM) is set by a particle asymmetry, similar to baryonic matter. Annihilation-like indirect detection signals are not typically expected in the simplest models of this type, as the DM is non-self-conjugate and the relic density of anti-DM is negligible. However, for non-minimal models observable annihilation signals can occur and I will highlight some motivated models which accomplish this.
Jaroslav Trnka (Caltech): "The Amplituhedron" | Mar 19
In this talk we show that scattering amplitudes in N=4 SYM can beunderstood as volumes of “The Amplituhedron”, a natural generalization of convex polygons into the Grassmannian. This invariant definition of the amplitude makes no reference to the usual concepts of quantum field theory. All fundamental properties of the amplitude, such as Unitarity, Locality follow from positivity. Any representation of the amplitude can be then understood as a particular triangulation of this object.
Sera Cremonini (Texas A&M): "Probing the deep IR of scaling geometries" | Mar 26
Over the past decade holography has been used as a laboratory to probe systems whose underlying degrees of freedom are strongly coupled and therefore difficult to study using traditional methods.
In this talk I will discuss certain classes of geometries which exhibit anisotropic scalings and have served as toy models for describing quantum critical points and strongly correlated electron systems.
In particular, I will focus on the behavior of such scaling solutions in the deep infrared, and show that they may be unstable to the formation of spatially modulated phases.
Yonit Hochberg (Berkeley): "The SIMP miracle" | Apr 2
We present a new paradigm for achieving thermal relic dark matter. The mechanism arises when a nearly secluded dark sector is thermalized with the Standard Model after reheating. The freezeout process is a number-changing 3 \to 2 annihilation of strongly-interacting-massive-particles (SIMPs) in the dark sector, and points to sub-GeV dark matter. The couplings to the visible sector, necessary for maintaining thermal equilibrium with the Standard Model, imply measurable signals that will allow coverage of a signifi.cant part of the parameter space with future indirect and direct detection experiments and via direct production of dark matter at colliders. Moreover, 3 \to 2 annihilations typically predict sizable 2 \to 2 self-interactions which naturally address the `core vs. cusp' and `too-big-to-fail' small structure problems.
Nabil Iqbal (UC Santa Barbara): "Holographic Entanglement Entropy and Gravitational Anomalies" | Apr 9
A quantum field theory can suffer from gravitational anomalies which render its stress tensor non-conserved at the quantum level, e.g. a 2d CFT with different left and right central charges. Such a 2d CFT has a dual gravitational description given by topologically massive gravity. I will discuss work in progress towards the computation of entanglement entropy in such a theory from its gravity dual, and explain how the anomaly has the effect of broadening the Ryu-Takayanagi minimal worldline into a “ribbon” whose twisting carries nontrivial information.
Ben Heidenreich (Harvard): "Natural Supersymmetry in Warped Space" | Apr 16
I discuss the possibility that a natural model of TeV-scale physics could incorporate both supersymmetry and a warped extra dimension. I argue that, in its simplest form, such a "SUSY RS" model naturally includes R-parity violation, and I describe a simple example with light stops, a Higgsino LSP decaying via three jets, and TeV-scale gauginos. The remaining squarks and sleptons are decoupled, suppressing flavor and baryon-number violation to acceptable levels. While the missing superpartners lead to quadratic divergences in the effective theory, naturalness can be maintained if the compactification scale is sufficiently low. I discuss a generic problem with models of this type, along with potential solutions.
Eric Perlmutter (DAMTP): "Entanglement in General Holgraphic CFTs" | May 16
There has been phenomenal recent progress in computing entanglement and Renyi entropy in conformal field theories with pure gravity duals. In an effort to elucidate the intersection of holography, entanglement and the fundamental structure of CFTs, we extend these methods to more general CFTs and their gravity duals. We focus mostly on AdS_3/CFT_2. First, we work in the realm of higher spin holography, by computing ground state entanglement and Renyi entropy in certain classes of holographic 2d CFTs with higher spin symmetry. This involves a precise match between CFT and higher spin gravity calculations, performed at both leading and next-to-leading order in large central charge (small Newton's constant). We will also present results on entanglement entropy in 2d CFTs with a gravitational anomaly. Time permitting, we will discuss purely field-theoretic methods for computing Renyi entropy in generic CFTs in any spacetime dimension, and apply them to the 3d O(N) vector model coupled to a Chern-Simons gauge field at large N.
Wei Xue (SISSA): "Composite Strongly Interacting Dark Matter" | May 28
It has been suggested that cold dark matter has difficulties in explaining tentative evidence for noncuspy halo profiles in small galaxies, and the low velocity dispersions observed in the largest Milky Way satellites ("too big to fail" problem). Strongly self-interacting dark matter has been noted as a robust solution to these problems. The elastic cross sections required are much larger than predicted by generic CDM models, but could naturally be of the right size if dark matter is composite. I will present a general way on constraining models where strongly interacting CDM is in the form of dark "atoms" or "molecules", or bound states of a confining gauge interaction ("hadrons").
