### September 19, 2011

Speaker:  Sergei Dubovsky, New York University

### September 26, 2011

Speaker: Emil Mottola, Los Alamos National Laboratory

Abstract:

Anomalies are classical symmetries that cannot be maintained at the quantum level. In the familiar axial anomaly in QED and QCD, massless poles necessarily arise from anomalous Ward identities. These massless poles in two-particle intermediate states are non-local quantum pair correlated states, described by an effective local Lagrangian containing additional pseudoscalar degrees of freedom, not present in the classical theory. The stress tensor contains a similar anomaly in its trace, which leads to additional scalar degrees of freedom not present in the classical Einstein theory. Thus General Relativity receives quantum corrections from Standard Model fields which can become significant in macroscopic systems and in particular near black hole and cosmological event horizons.

The region near the classical event horizon of a fully collapsed star may then be instead a quantum boundary layer where the effective value of the gravitational vacuum energy density can change. By taking a positive value in the interior, the vacuum energy removes any singularity, replacing it with a smooth dark energy interior.
The observed dark energy of our universe likewise may be a macroscopic finite size effect
whose value depends not on microphysics but on the cosmological horizon itself.

### October 3, 2011

Speaker:  Yasunori Nomura, University of California, Berkeley

Abstract:

I describe how quantum mechanics plays a crucial role in defining probabilities (the "measure") in the multiverse. The resulting picture leads to a dramatic change of our view on spacetime and gravity, and provides complete unification of the eternally inflating multiverse and many worlds in quantum mechanics. The latest result on the distribution of the cosmological constant is also presented.

### October 10, 2011

Speaker:  Daniel Green, Institute for Advanced Study, Princeton University

Abstract:

Supersymmetry plays a fundamental role in the radiative stability of many inflationary models.  I will explain how supersymmetry and naturalness require additional scalar degrees of freedom with masses on the order of the inflationary Hubble scale.  These fields lead to distinctive non-gaussian signatures that may be observable in both the CMB and large scale structure.

### October 17, 2011

Speaker: Professor Antonio Delgado, Notre Dame University

Abstract:

The LEP bound on the Higgs mass has created a problem within the MSSM, the little hierarchy problem. I will present a model in which that problem is solved via a singlet whose sole role is to increase the Higgs mass at tree-level and not to solve the mu problem as in the usual NMSSM.

### October 24, 2011

Speaker: Rafael Porto, Institute for Advanced Study

Abstract:

Using an approach originally developed to study gravitational wave absorption in black hole binary systems, we generalize the EFT of single clock inflation to include dissipative effects. We show that in the presence of dissipation/fluctuation the computation of the power spectrum is significantly modified, and moreover non-gaussianities can be enhanced with respect to the case without additional degrees of freedom by a factor of \gamma/H, where \gamma is the `friction' coefficient. We also discuss the matching of the EFT with a few key examples such as trapped and warm inflation.

### October 31, 2011

Speaker: Ben Freivogel, University of California, Santa Barbara

### November 14, 2011

Speaker: Professor Zohar Komargodski,Weizmann/IAS Princeton

Abstract:

If the coupling constants in a general QFT are promoted to functions of space-time, the dependence of the path integral on these couplings  is highly constrained by conformal symmetry. We use this simple observation to derive the $a$-theorem. We also study simple examples of the general procedure. Finally, we discuss the dependence on the coupling constants in arbitrary two-dimensional RG flows. The constraints of conformal symmetry lead to a new proof of Zamolodchikov's theorem.

### December 5, 2011

Speaker: Raphael Bousso, UC Berkeley

Abstract:

Without assuming necessary conditions for observers such as galaxies or entropy production, we show that the causal patch measure predicts the coincidence of vacuum energy and present matter density. Their common scale, and thus the enormous size of the visible universe, has its origin in the number of metastable vacua in the landscape.

### December 19, 2011

Speaker:  Mark Jackson, APC Paris

Abstract:

Although the observed CMB is at very low energy, it encodes ultra high-energy physics in spatial variations of the photon temperature and polarization fluctuations. This effect is believed to be dominated by the initial quantum state of the Universe.  I will describe the first theoretical tools by which to construct such a state from fundamental physics.  One can then use this technique to reliably calculate corrections to the power spectrum, non-Gaussianity, etc from high-energy physics.  We may soon be able to compare these predictions against experiment, allowing one to rule out classes of quantum gravity models.  Now is the critical time to undertake such investigations, with a number of ongoing and planned experiments such as Planck and CMBPol/Inflation Probe poised to collect a wealth of precision data.