Place: DRL 2N36
Time: 2 pm
Events
Time: 2 pm
Place: DRL 2N36
Electroweak stars: Electroweak Matter Destruction as Exotic Stellar Engine
Stellar evolution from a protostar to neutron star is of one of the best studied subjects in modern astrophysics. Yet, it appears that there is still a lot to learn about the extreme conditions where the fundamental particle physics meets strong gravity regime. After all of the thermonuclear fuel is spent, and after the supernova explosion, but before the remaining mass crosses its own Schwarzschild radius, the temperature of the central core of the star might become higher than the electroweak symmetry restoration temperature. The source of energy, which can at least temporarily balance gravity, are baryon number violating instanton processes which are basically unsuppressed at temperatures above the electroweak scale. We constructed a solution to the Oppenheimer-Volkoff equation which describes such a star. The energy release rate is enormous at the core, but gravitational redshift and the enhanced neutrino interaction cross section at these densities make the energy release rate moderate at the surface of the star. The lifetime of this new quasi-equilibrium can be more than ten million years, which is long enough to represent a new stage in the evolution of a star.
Time: 2 pm
Place: DRL 2N36
TBA
Time: 2pm
Place: DRL 2N36
Stochastic Gravitational Wave Backgrounds and Astrometry
Abstract: A stochastic gravitational wave background causes the apparent positions of distant sources to fluctuate, with angular deflections of order the characteristic strain amplitude of the gravitational waves. These fluctuations may be detectable with high precision astrometry, as first suggested by Braginsky et al. in 1990. Several researchers have made order of magnitude estimates of the upper limits obtainable on the gravitational wave spectrum \Omega_gw(f), at frequencies of order f ~ 1 yr^-1, both for the future space-based optical interferometry missions GAIA and SIM, and for VLBI interferometry in radio wavelengths with the SKA. For GAIA, tracking N ~ 10^6 quasars over a time of T ~ 1 yr with an angular accuracy of \Delta \theta ~ 10 \mu as would yield a sensitivity level of \Omega_gw ~ (\Delta \theta)^2/(N T^2 H_0^2) ~ 10^-6, which would be roughly comparable with pulsar timing. We take a first step toward firming up these estimates by computing in detail the statistical properties of the angular deflections caused by a stochastic background.
We compute analytically the two point correlation function of the deflections on the sphere, and the spectrum as a function of frequency and angular scale. The fluctuations are concentrated at low frequencies (for a scale invariant stochastic background), and at large angular scales, starting with the quadrupole. The magnetic-type and electric-type piecesof the fluctuations have equal amounts of power. [based on Laura Book, EF, Phys. Rev. D 83, 024024 (2011)]
Time: 2 pm
Place: DRL 2N36
3d Domain Walls of Class R
Time: 1:30pm
Place: DRL 3C8
Abstract: I will discuss recent work with D. Gaiotto and S. Gukov on associating 3d superconformal field theories
to 3-manifolds, and touch upon some new work in constructing domain walls for 4d N=2 theories this way.
Neutrino telescopes and atmospheric neutrino oscillations in the era of "high precision neutrino physics"
Abstract: After an introduction to the present status of neutrino oscillation physics and the questions that are still to be answered, I will discuss the potential of neutrino telescopes to help improve our knowledge of particle physics and astrophysics. I will then concentrate on the analysis of atmospheric neutrinos in the IceCube Deep Core detector and its possible extensions. I will discuss how this data can greatly improve our understanding of neutrino oscillations and, potentially, new physics.
Time: 2 pm
Place: DRL 2N36
Cusped Wilson loops in N=4 super Yang-Mills
Time: 2:00pm
Place: DRL 2N36
Omega-deformation of rigid N=2 theories
Time: 1:30 pm
Place: DRL 3C8
Abstract:
We obtain analytic expressions for the topological partition function of arbitrary N=2 theories in 4d using modularity, the holomorphic anomaly and boundary conditions. If a region of asypmotic freedom exists they specialize to Nekrasovs partition function.
For topological string theory on non-compact Calabi-Yau manifolds defined by the anticanonical bundle over del Pezzo surfaces the partition function counts motivic Donaldson-Thomas invariants related to stable pairs with support on the del Pezzo surface.
The Wasteland of Random Supergravities
Time: 2 pm
Place: DRL 2N36
Fermi surfaces, degenerate black holes and quasi-normal modes
Time: 2pm
Place: DRL 2N36
Black holes as Rubik's Cubes
Time: 2pm, Monday
Place: 2N36
From M-theory to F-theory at one loop
Time: 2pm (Tuesday)
Place: DRL 4N12
Main Venue: David Rittenhouse Lab. (DRL), Room 3W2. 33rd and Walnut St.
Directions: Enter the building through the 33rd St. entrance. If you arrive late, don't go to the Center on the 4th floor, but come up to 3W2 directly through the doors on the left.
Time: 10:30 am - 5:30 pm
Organizers: Jean O'Boyle and Yi-Zen Chu (yizen [dot] chu [at] gmail [dot] com)
Morning Session
- 10:30 am - 11:00 am: Welcome coffee at the Center for Particle Cosmology, DRL 4th floor
- 11:00 am - 11:10 am: DRL Room 3W2 (Main venue for talks)
- Welcome and opening remarks by Mark Trodden
- 11:10 am - 11:50 am (30+10 min)
- Speaker: Melinda Andrews, UPenn
- Title: PPN for Theories with Screening Mechanisms
- Abstract: The parametrized post-Newtonian expansion has a long history of being useful for testing gravity in the small-velocity regime, and is unexpectedly also quite useful in the prediction of gravitational waves produced by compact object binaries. However, the existence of screening mechanisms in various modified gravity theories (as an example of which I will discuss the Vainshtein screening mechanism of galileon theories) complicates the traditional expansion procedure. In the presence of degrees of freedom which even in the weak-gravity regime are significantly different than their cosmological value, it is useful to proceed using the EFT approach of hep-th/0409156 and 0812.0012. I will discuss how to extend this procedure to the case of galileons in the absence of gravity.
- 11:50 am - 12:30 pm (30+10 min)
- Speaker: Godfrey Miller, UPenn
- Title: Spatially Covariant Theories of a Transverse, Traceless Graviton
- Abstract: General relativity is a covariant theory of two transverse, traceless graviton degrees of freedom. According to a theorem of Hojman, Kuchar, and Teitelboim, modifications of general relativity must either introduce new degrees of freedom or violate the principle of general covariance. In my talk, I will discuss modifications of general relativity that retain the same number of gravitational degrees of freedom, and therefore explicitly break general covariance. Motivated by cosmology, the modifications of interest maintain spatial covariance. Demanding consistency of the theory forces the physical Hamiltonian density to obey an analogue of the renormalization group equation, which encodes the invariance of the theory under flow through the space of conformally equivalent spatial metrics.
Lunch Break
- 12:30 pm - 1:40 pm: Lunch at the Center for Particle Cosmology, DRL 4th floor.
Afternoon Session I of II
- 1:40 pm - 3 pm
- Talks by Eric Greenwood (Part A, 30+10 min) and Dmitry Podolsky, (Part B, 30+10 min), CWRU
- Joint Title: Kinetics and thermalization of Hawking radiation
- Abstract: Hawking's discovery of black holes radiance along with Bekenstein's conjecture of the generalized second law of thermodynamics inspired a conceptually pleasing connection between gravity, thermodynamics and quantum theory. However, the discovery that the spectrum of the radiation is in fact thermal, together with the no-hair theorem, has brought along with it some undesirable consequences, most notably the information loss paradox. There have been many proposals to the resolution of this paradox, with the most natural resolution being that during the time of collapse the radiation given off is not completely thermal and can carry small amounts of information with it. In this talk, we will revisit the Hawking radiation given off during the scenario of gravitational collapse by utilizing th functional Schroedinger equation (FSE) and deriving quantum kinetic equation for the spectrum of Hawking radiation. We will show that the spectrum never becomes thermal and discuss the reasons for this. Finally we will discuss the implications of this result, as well as previous results, toward the resolution of the information paradox.
- 1:40 pm - 2:20 pm: (30+10 min)
- Part A Speaker: Eric Greenwoord
- Part A Abstract: Heisenberg quantization of QFT on collapsing spacetime background; functional Schrodinger equation for the wavefunction of Hawking radiation; derivation of quantum kinetic equation for the spectrum of Hawking radiation; IR part of the spectrum.
- 2:20 pm - 3 pm: (30+10 min)
- Part B Speaker: Dmitry Podolsky
- Part B Abstract: IR part of the spectrum, UV part of the spectrum; adiabatic renormalization for UV tail in CGHS scenario of collapse; implications for information loss paradox.
Coffee Break
- 3 pm - 3:40 pm: Coffee break
Afternoon Session II of II
- 3:40 pm - 4:00 pm (15+5 min)
- Speaker: Victor Gorbenko, NYU
- Title: Lorentz Symmetry of Effective Strings Via the Evanescent Einstein Term
- 4:00 pm - 4:20 pm (15+5 min):
- Speaker: Keith Chan, NYU
- Title: Gravity and non-local large-scale bias
- 4:20 pm - 4:40 pm (15+5 min)
- Speaker: Mehrdad Mirbabayi, NYU
- Title: Degrees of freedom in massive gravity
- 4:40 pm - 5:00 pm (15+5 min)
- Speaker: Lasha Berezhiani, NYU
- Title: On black holes in massive gravity
End of Program
Solid Inflation
Time: 2pm
Place: DRL 2N36
The resolved geometry of SU(5) GUTs
Time: 2pm (Monday)
Place: DRL 2N36
The Effective Theory of the Long Distance Universe
Time: TBA
Place: TBA
Counting Degrees of Freedom in 3-d Conformal Field Theory
Time: 2pm (Monday)
Place: DRL 2N36
Five-dimensional gauge theory and compactification on a torus
Time: 2pm (Monday)
Place: DRL 2N36
We study five-dimensional minimally supersymmetric gauge theory compactied on a torus down to three dimensions, and its embedding into string/M-theory using geometric engineering. The moduli space on the Coulomb branch is hyperkaehler equipped with a metric with modular transformation properties. We determine the one-loop corrections to the metric and show that they can be interpreted as worldsheet and D1-brane instantons in type IIB string theory. Furthermore, we analyze instanton corrections coming from the solitonic BPS magnetic string wrapped over the torus. In particular, we show how to compute the path-integral for the zero-modes from the partition function of the M5 brane, or, using a 2d/4d correspondence, from the partition function of N=4 SYM theory on a Hirzebruch surface.
The phenomenology of light gravitino dark matter
Time: 3pm (Thursday)
Place: 4N12
I will discuss some work on the collider phenomenology and cosmology of light gravitino dark matter, as well as some related issues concerning infrared divergences in charged-particle decay at finite temperature.
Light gravitinos, with mass in the eV to MeV range, are well-motivated in particle physics, but their status as dark-matter candidates is muddled by early-Universe uncertainties. Upcoming data from colliders may clarify this picture. Light-gravitino collider events should result in spectacular signals, including di-photons, delayed and non-pointing photons, kinked charged tracks, and heavy metastable charged particles. Remarkably, collider data is also well suited to distinguish between currently viable light-gravitino cosmological scenarios, with interesting implications for early-Universe cosmology. Finally, the process of charged-particle decay in the early Universe is important in light-gravitino production, and may also be relevant in other particle-astrophysics scenarios. I will examine the cancellation of power-like infrared divergences that arise at finite temperature, and will discuss some possible implications for such scenarios.
