Joint Theory Seminar
Speaker: Bibhushan Shakya (Michigan)
Title: Neutrino Masses and Sterile Neutrino Dark Matter from the PeV Scale
Host: Yuhsin
Room: 432
Abstract: The Higgs boson mass of 125 GeV is suggestive of superpartners at the PeV scale. This talk discusses how new physics at this scale can also produce active neutrino masses via a modified, low energy seesaw mechanism and provide a sterile neutrino dark matter candidate with keV-GeV scale mass. These emerge in a straightforward manner if the right-handed neutrinos are charged under a new symmetry broken by a scalar field vacuum expectation value at the PeV scale. Possible connections to the 3.5 keV X-ray line and the PeV neutrino events at IceCube will also be discussed.
User:
High-Energy Seminars
Time:
8:10am - 9:00am
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Yes - 0 days 4 hour 0 minutes before start
Description:
Speaker: Andrew Neitzke, UT Austin
Date: Tue Feb. 3
Time: 4:10 PM (Refreshments 20 minutes before talk)
Location: 1147 MSB
Title: The many uses of BPS particles
Abstract: "BPS particles" are certain distinguished objects which
arise in supersymmetric quantum field theory. You do not have to know
what they are to understand this talk: I will focus on a simple class
of examples which are geometrically concrete and self-contained, where
BPS states correspond to certain special geodesics or geodesic webs on
Riemann surfaces. In the last few years it has been understood that
BPS states are connected to various other problems in mathematics and
physics, ranging from hyperkahler geometry to analysis of ODEs,
cluster algebras, and Chern-Simons theory. I will give an overview of
the story. Most of the work I review is joint work with Davide Gaiotto
and Greg Moore; I will also touch on some upcoming work with Dan
Freed.
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High-Energy Seminars
Time:
5:10am - 6:00am
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Yes - 0 days 1 hour 0 minutes before start
Description:
Special Math/Physics Seminar
Speaker: Christopher Herzog
Room: 432
Title: The Structures of Entanglement
Abstract: Entanglement entropy plays a large role in theoretical physics today in quantum mechanics, condensed matter physics, quantum field theory, gravity, and even string theory. I will discuss some of the recent successful applications of entanglement ideas and also some of the challenges we still face. The second half of the talk will largely be devoted to recent progress in understanding thermal corrections to entanglement entropy.
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High-Energy Seminars
Time:
6:20am - 7:30am
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Description:
Speaker: Daniel Litim, University of Sussex
(Visitor to Steve Carlip's quantum gravity class, giving a
seminar open to all.)
Room: 185
Host: Carlip
Title: Interacting UV fixed points - from 4D quantum gauge
theories to 4D quantum gravitation
Abstract:
It is commonly believed that a fundamental definition of
quantum field theory requires the existence of an UV fixed
point. Asymptotic freedom of QCD is the well-known
example where the fixed point is non-interacting. In this talk, I provide a proof of existence for novel classes of 4D
matter-gauge theories whose high-energy behaviour is
governed by an interacting UV fixed point. In the absence
of asymptotic freedom, scalars, fermions, and non-Abelian
gauge fields cooperate in such a way that an interacting
UV fixed point emerges. I discuss the key characteristics
of these theories which are all under strict perturbative
control. I also discuss recent advances and challenges to
find interacting UV fixed points in 4D quantum gravity
once couplings become strong.
User:
High-Energy Seminars
Time:
3:00am - 4:00am
Description:
Terning group meeting
User:
High-Energy Seminars
Time:
5:10am - 6:00am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Special Math/Physics Seminar
Speaker: Sergei Dubovsky
Title: On the hierarchy problem
Host: Markus Luty
Room: 432
Abstract: The origin of the huge hierarchy between the electroweak and the Planck scales
remains the major problem driving the development of particle physics and quantum field theory over the last four decades. I will review the conventional views on its resolution, which is either emergence of new physics at the TeV scale or anthropic fine-tuning. Then I will explore an alternative: the "third way", involving a refined notion of naturalness. I will describe a family of toy UV complete quantum theories providing a proof of concept for this possibility. In these models low energy physics is described by a tuned effective field theory, which exhibits relevant interactions not protected by any symmetries that are separated by an arbitrarily large mass gap from the new gravitational physics, represented by a set of irrelevant operators. Despite this scale separation, the only available language to describe dynamics at all energy scales does not require any fine-tuning. An interesting novel feature of this construction is that UV physics is not described by a fixed point and is governed by a novel type of asymptotic behavior.
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High-Energy Seminars
Time:
8:00am - 9:00am
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Description:
HE Seminar
Speaker: Aaron Manalaysay
Title: Dark Matter and Liquid Xenon
Host: Mani Tripathi
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
5:10am - 6:00am
Description:
Speaker: Liam Fitzpatrick
Room: Physics 432
Title: Universal Dynamics from the Conformal Bootstrap
Abstract: Conformal Field Theories (CFTs) play a central role in understanding strongly coupled physics across a wide range of phenomena. One of the most powerful tools for studying them is the Conformal Bootstrap, which in the past several years has seen renewed interest and tremendous progress in its applications. In this talk, we discuss how the Conformal Bootstrap can be used to uncover and prove universal dynamical behavior that is satisfied by all CFTs in some limits, and large classes of them in other limits. Through the Anti-de Sitter/CFT (AdS/CFT) correspondence, these results can be interpreted to imply universal aspects of dynamical behavior of the dual gravitational theories, including locality and the emergence of Newtonian gravity at large distances. For CFTs in two dimensions, we demonstrate how in systems with a large number of degrees of freedom, high energy eigenstates can be shown to create classical backgrounds. This can be directly related to black hole geometries in a semi-classical limit of the gravitational duals, and to a phenomenon known as Eigenstate Thermalization whereby pure states mimic thermal backgrounds in the CFT. Methods for going beyond the semi-classical limit of gravity are discussed.
User:
High-Energy Seminars
Time:
3:00am - 4:00am
Description:
Terning group meeting
Description:
Valentine's Day
Description:
Presidents' Day
User:
High-Energy Seminars
Time:
8:00am - 9:00am
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Description:
HE Seminar
Speaker: Surjeet Rajendran
Title: Searches for ultralight hidden photons
Host: Tripathi
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
5:10am - 6:00am
Description:
Special Seminar
Speaker: Chris Beem
Room: 432
Title: Studying challenging theories with the superconformal bootstrap
Abstract: Despite its tremendous theoretical and experimental successes, there are good reasons to think that our current understanding of quantum field theory is incomplete in important ways. One of these reasons is the apparent existence of quantum field theories that cannot be given a conventional definition in terms quantum fields and Lagrangians. In this talk, I will introduce such a puzzling class of interacting quantum field theories in six dimensions that have resisted direct analysis since their discovery in the 90s. I will then describe an algebraic approach to these theories based on the superconformal bootstrap. This approach has led to the first exact calculations of correlation functions in these theories and appears to provide a useful framework for their systematic analysis.
User:
High-Energy Seminars
Time:
3:00am - 4:00am
Description:
Terning group meeting
User:
High-Energy Seminars
Time:
5:10am - 6:00am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:
Title:
Host:
Room: 432
Abstract:
Abstract: Classical general relativity describes the dynamics of gravity through the Einstein's equations, while relativistic fluids are governed by a generalization of the famous Navier-Stokes equations. Though a-priori we don't tend to think of these two physical systems in the same breath, I will argue that in a certain dynamical regime, the gravitational equations precisely become those of fluid dynamics. This statement, which embodies the fluid/gravity correspondence, has over the past few years not only helped us in understanding the transport properties of some strongly coupled systems, but is proving to be a prototype for the development of an autonomous theory of hydrodynamics. I will explain the basic statement of the correspondence and the lessons we have learned from it, focussing on the development of a Wilsonian effective field theory for thermal systems.