Fine Theoretical Physics Institute Seminar

semester, 2018


Monday, January 29th 2018
3:30 pm:
FTPI Special Seminar in Tate 301-20
Speaker: Maxim Pospelov
Subject: "Widening the net in search for New Physics"
Candidate for FTPI Faculty Position

Following spectacular confirmation of the Standard Model at the LHC, the emphasis of particle physics shifts towards searches for physics beyond Standard Model. The clues for new physics may be hidden in cosmological data that suggest the dominance of dark matter and dark energy throughout the Universe. I will describe some recent aspects of widening the search for new physics focussing on light dark matter and in general on light weakly coupled states. I will introduce constraints on dark matter - electron scattering that result from a new phenomenon, the reflection of dark matter from the solar interior. I will also argue that besides conventional probes of light weakly coupled states, further insight can be gained by involving precision AMO tools, and describe some recent experimental activity in this direction.

Faculty Host: Keith Olive

Tuesday, January 30th 2018
1:00 pm:
FTPI Special Seminar in Tate 201-20
Speaker: Maxim Pospelov
Subject: "Light Z' coupled to poorly conserved currents"
Candidate for FTPI Faculty Position
Faculty Host: Keith Olive

Monday, February 12th 2018
3:30 pm:
Speaker: Katherine Freese
Subject: The Dark Matter in the Universe
Candidate for FTPI Faculty Position

“What is the Universe made of?” This question is the longest outstanding problem in all of modern physics, and it is one of the most important research topics in cosmology and particle physics today. The bulk of the mass in the Universe is thought to consist of a new kind of dark matter particle, and the hunt for its discovery in on. I'll start by discussing the evidence for the existence of dark matter in galaxies, and then show how it fits into a big picture of the Universe containing 5% atoms, 25% dark matter, and 70% dark energy. Neutrinos only constitute ½% of the content of the Universe, but much can be learned about neutrino properties from cosmological data. Leading candidates for the dark matter are Weakly Interacting Massive Particles (WIMPs), axions, and sterile neutrinos. WIMPs are a generic class of particles that are electrically neutral and do not participate in strong interactions, yet have weak-scale interactions with ordinary matter. There are multiple approaches to experimental searches for WIMPS: at the Large Hadron Collider at CERN in Geneva; in underground laboratory experiments; with astrophysical searches for dark matter annihilation products, and upcoming searches with the James Webb Space Telescope for Dark Stars, early stars powered by WIMP annihilation. Current results are puzzling and the hints of detection will be tested soon. At the end of the talk I'll briefly turn to dark energy and its effect on the fate of the Universe.

Faculty Host: Keith Olive

Tuesday, February 13th 2018
1:00 pm:
FTPI Special Seminar in Tate 201-20
Speaker: Katherine Freese
Subject:  Inflationary Cosmology: Theoretical Developments and Status in light of Cosmic Microwave Background Data
Candidate for FTPI Faculty Position
Faculty Host: Keith Olive

Monday, February 19th 2018
3:30 pm:
Speaker: Mithat Unsal
Subject: Decoding path integrals: Resurgence and mass gap
Candidate for FTPI Faculty Position

I will provide an introductory level overview of recent
applications of resurgent trans-series and Picard-Lefschetz theory to
quantum mechanics and quantum field theory.
Resurgence connects local perturbative data with global topological
structures. In quantum mechanical systems, this program provides a
constructive relation between different saddles. For example, in
certain cases it has been shown that all information around the
instanton saddle is encoded in perturbation theory around the
perturbative saddle. In quantum field theory, such as sigma-models
compactified on a circle, neutral bions provide a semi-classical
interpretation of the elusive IR-renormalon, and fractional kink
instantons lead to the non-perturbatively induced mass gap exactly of
order of the strong scale. I also describe the concept of hidden
topological angle, a phase associated with Lefschetz thimbles.
Hidden topological angle may provide destructive/constructive
interference effects between equally dominant saddles in the Lefschetz
thimble decomposition, providing resolution to some time standing
puzzles in non-perturbative analysis.

Faculty Host: Keith Olive

Tuesday, February 20th 2018
1:00 pm:
FTPI Special Seminar in Tate 201-20
Speaker: Mithat Unsal
Subject: Phase transitions, semi-classics and anomalies
Candidate for FTPI Faculty Position
Faculty Host: Keith Olive

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