Joint Theory Seminar
Speaker: James Scargill (UC Davis)
Title: Unusual vacuum decay events in the early universe
Host:
Room: 432
Abstract: Quantum transitions between different vacua may be important in the early universe; for instance our universe could directly arise from such a transition followed by a period of inflation. In this talk I will consider in such a context transitions which change the number of large dimensions of the universe, and discuss their observational signatures on the cosmic microwave background. I will also briefly discuss a class of O(3) symmetric vacuum decays which have been argued to be competitive with bubble collisions in the early universe.
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:Isabel Garcia Garcia (Oxford)
Title: The String Soundscape at Gravitational Wave Detectors
Host:Verhaaren
Room: 432
Abstract: In this talk, we explore the possibility of gravitational wave production due to ultra-relativistic bubble wall collisions. This occurs due to a process of post-inflationary vacuum decay that takes place via quantum tunneling within a warped throat (of Randall-Sundrum type). We emphasize the differences between vacuum decay via quantum tunneling, and a thermal first order phase transition, and how potential gravitational wave signals from both processes differ. We explore a specific example in the context of type IIB string theory, although we argue that our conclusions are more generally applicable to theories with hidden sectors featuring metastable vacua. Many such transitions could have occurred in the post-inflationary Universe, as a large number of throats with exponentially different IR scales can be present in the string landscape, potentially leading to several signals of widely different frequencies – a soundscape connected to the landscape of vacua. Future detectors like LISA will have the required sensitivity to detect these potential signals.
User:
High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 4 hour 0 minutes before start
Description:
High Energy Seminar
Speaker: Yasha Neiman (OIST)
Title: Both AdS and CFT from twistor space
Host: Andreas Albrecht
Room: 285
Abstract: We consider one of the simplest holographic models: higher-spin gravity in 4 dimensions vs. a free vector model in 3 dimensions. We present a picture in which both the bulk and boundary local descriptions descend from a unified description in twistor space. Higher-spin gravity is closely tied to the Penrose transform, which relates bulk massless fields to twistor functions. We develop a new geometric perspective on the Penrose transform, whereby it becomes a peculiar representation of a CPT reflection. We then identify a boundary version of the transform, relating twistor functions to bilocal operators and sources in the CFT. This allows us to write the partition function in manifestly higher-spin-covariant language, line by line in the Feynman diagrams. The famous ambiguity in the bulk Penrose transform becomes related to the gauge redundancy in the boundary sources.
Description:
St Patrick's Day
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker: Francesco Riva
Title: Precision Tests in the High Energy Era
Host: Luty
Room: 432
Abstract: With increasing integrated luminosity, precision tests of the SM are gaining importance as New Physics search tools at the LHC. I focus on precision studies of SM processes at high-energy and on the challenges that this program faces from a BSM perspective. In particular I discuss the implications of interesting BSM-SM non-interference rules and describe broad scenarios of vector/fermion/scalar compositeness that constitute the primary target for this type of searches.
User:
High-Energy Seminars
Time:
5:30am - 6:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:
Title:
Host:
Room: 432
Abstract:
