November 28, 2022 Monday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
CCPP Brown Bag
Fedor Popov
New York University
Conformal Field Theories and Tensor Models
November 29, 2022 Tuesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
ASTRO Journal Club
November 29, 2022 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Yuri Levin
Columbia University
Resonant Friction on discs in galactic nuclei
Statistical physics has a bad track record in describing large-N gravitational systems. It has become clear over the last several years that there is a remarkable exception to this rule. Resonant relaxation due to orbit-averaged secular dynamics in galactic nuclei drives them to states of thermal and rotational equilibria on an astronomically short timescale. There are fun applications: phase transitions leading to lopsided precessing equilibria (similar-looking to the nucleus of Andromeda), and strong clustering in eccentricity and inclination of stellar-mass black holes. Following Rauch and Tremaine, I will use statistical physics to argue that secular-dynamical "resonant friction" must exist and that moreover, it likely
plays a huge role in galactic nuclei. It controls the dynamics of Intermediate-Mass Black Holes as well as that of stellar and accretion discs. The young stellar disc at the center of our Galaxy presents a good case study for this effect.
November 30, 2022 Wednesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
HEP Journal Club
November 30, 2022 Wednesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Shu-Heng Shao
Stony Brook
Non-invertible Symmetries in Nature
In massless QED, we find that the classical U(1) axial symmetry is not completely broken by the Adler-Bell-Jackiw anomaly. Rather, it is resurrected as a generalized global symmetry labeled by the rational numbers. Intuitively, this new global symmetry in QED is a composition of the naive axial rotation and a fractional quantum Hall state. The conserved symmetry operators do not obey a group multiplication law, but a non-invertible fusion algebra. We further generalize our construction to QCD, and show that the neutral pion decay can be derived from a matching condition of the non-invertible global symmetry. Finally, we find a non-invertible Gauss law in axion-Maxwell theory.
December 1, 2022 Thursday 4:00 PM
+
Zoom
Physics Colloquia
(
colloquia)
Chandralekha Singh
University of Pittsburgh
Facilitating Thinking and Learning In and Beyond the Physics Classrooms using Research-based Approaches
I will discuss, using my research in physics education, how research can be used as a guide to develop curricula and pedagogies to reduce student difficulties and for making physics equitable and inclusive. I will also discuss innovations in teaching and learning methods for physics after the new normal using my research conducted during emergency remote teaching and lessons learned that can be valuable for innovation in teaching and learning going forward. My research has focused on improving student understanding of introductory and advanced concepts. We are developing research-validated learning tools such as tutorials and peer instruction tools that actively engage students in the learning process. I will discuss how we evaluate the effectiveness of these tools using a variety of methodologies and then describe our research studies that provide guidelines for how to enhance physics by making it inclusive. Finally, I will discuss how a field-tested short intervention was implemented at the beginning of a physics course and how it improved the performance of underrepresented students in introductory physics classes compared to the comparison group.
December 5, 2022 Monday 11:00 AM
+
726
Broadway, Room 1067
Center for Quantum Information Physics Seminars
(
cqip)
Andrea Cavalleri
Max Planck Institute for the Structure and Dynamics of Matter| Department of Physics, Oxford
Photo-induced High Temperature Superconductivity
I will discuss how coherent optical pulses at mid infrared frequencies can be used to excite targeted
molecular vibrations in organic materials with strongly correlated electrons and manipulate their
electronic properties. I will discuss especially the case of charge transfer salts and of doped fullerites.
Both materials exhibit colossal increase in carrier mobility for certain vibrational excitations and key
signatures of photo-induced high temperature superconductivity.
December 5, 2022 Monday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
CCPP Brown Bag
Isabel Garcia Garcia
New York University
To Be Determined
December 5, 2022 Monday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Informal HEP Talk
Lingfeng Li
Brown
tba
December 6, 2022 Tuesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
ASTRO Journal Club
December 6, 2022 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Matias Zaldarriaga
Institute for Advanced Studies
To Be Determined
December 7, 2022 Wednesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
HEP Journal Club
December 8, 2022 Thursday 12:00 PM
+
American Museum of Natural History
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Big Apple Colloquium
Heidi Hammel
AURA
James Webb Space Telescope
December 8, 2022 Thursday 4:00 PM
+
Hybrid: 726
Broadway, 940 and Zoom
Physics Colloquia
(
colloquia)
Igor Klebanov
Princeton University
Strong Interactions, Confinement and Strings
In the 1950s and 60s many strongly interacting particles (mesons and baryons) were discovered. String theory was originally invented to describe them, but 50 years ago Quantum Chromodynamics (QCD) emerged as the precise theory of the strong nuclear force. A quarter century later it was understood that string theory and certain gauge theories akin to QCD are different descriptions of the same physics. I will review the relations between gauge theories and strings. The formation of QCD strings is a manifestation of the confinement of colored quarks and gluons. The confinement is observed numerically using Lattice Gauge Theory, and I will review evidence that large N QCD provides a good approximation to the masses of hadrons. The gauge/gravity duality has shed new light on confinement, but its analytic understanding remains a deep unsolved problem in theoretical physics. I will conclude by discussing some surprises in 2D models.
December 9, 2022 Friday 11:00 AM
+
726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Fei Yan
Rutgers
Entanglement entropy in (1+1)-d with defects
In this talk I will explore perspectives of quantum entanglement in (1+1)-d systems in presence of defects. The talk consists of two parts. In the first part, I will talk about the ground state entanglement entropy for 1d quantum spin chains with defects, using the transverse field Ising model and the three-state Potts model as examples. In the second part, I will comment on the field theoretical replica trick approach to study entanglement entropy in such systems.
December 9, 2022 Friday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Informal HEP Talk
Sangmin Choi
École Polytechnique
Holography from Singular Supertranslations on a Black Hole Horizon
We investigate the standard and dual BMS supertranslation generators on the black hole horizon and draw some conclusions about black hole physics. Recently, it has been shown that in addition to the conventional BMS supertranslation symmetries, there exists another infinite set of magnetic asymptotic symmetries that are referred to as dual BMS supertranslations. We show that the Dirac bracket between these generators exhibits a central term when the parameter functions have singularities in the complex stereographical coordinates on the sphere. Such singularities are related to Dirac-string-like configurations in the bulk, and should therefore be included in the set of acceptable transformations. We then demonstrate that this anomalous central term can be removed by including an appropriate gravitational Chern-Simons theory on the horizon. This implies that consistency of the asymptotic symmetry algebra requires a new structure on the horizon.
December 13, 2022 Tuesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
ASTRO Journal Club
December 13, 2022 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Blakesley Burkhart
Flatiron Institute
To Be Determined
December 13, 2022 Tuesday 4:00 PM
+
726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Adrian Tanasa
University of Bordeaux
Tensor models, large N limit and double scaling limit
Matrix models, seen as quantum field theoretical models, are known to represent a successful approach to 2D quantum gravity and to have many other interesting applications in Physics. Some of the main results of the study of matrix models in theoretical physics are the 't Hooft large N limit (the perturbative series can be reorganized in powers of 1/N (N being the matrix size)) and the double scaling limit mechanism (known to be related to the continuuos limit of the models).
After a brief introduction dedicated to matrix models, I will focus in this talk on tensor models, which are a natural quantum field theoretical generalization of these matrix models. In particular, I will present the implementation of the large N limit (N being now the size of the tensor) and the double scaling limit mechanisms for various tensor models, such as the O(N)³-invariant tensor model, initially introduced in O dimensions by Carrozza and Tanasa, arXiv:1512.06718, and then extended to the 1-dimensional case, by Klebanov and Tarnopolsky, arXiv:1611.08915. In the last part of the talk I will present how tensor models have been related (initially by Witten and then shortly after by Klebanov and Tarnopolsky) to the Sachdev-Ye-Kitaev model, which is known to be a particularly interesting toy model for holography.
December 14, 2022 Wednesday 12:30 PM
+
726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Other
HEP Journal Club
December 14, 2022 Wednesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Patrick Meade
Stony Brook
TBA
TBA
January 24, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Katie Breivik
Flatiron Institute
To Be Determined
January 31, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Sasha Tchekhovskoy
Northwestern University
To Be Determined
February 14, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Lam Hui
Columbia University
To Be Determined
February 21, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Tomer Yavetz
Institute for Advanced Studies
Stream Fanning and Bifurcations: Observing Fundamental Dynamics in Stellar Stream Morphology
Non-spherical gravitational potentials host a subset of resonantly-trapped orbit families surrounding special, closed orbits. The transitions between these orbit families, or separatrices, mark abrupt discontinuities in the orbital structure of the potential. I will show how the morphology of stellar streams can be used to identify and locate these separatrices, and discuss a few examples of observed streams with peculiar morphologies that may indicate the existence of a nearby dynamical resonance.
February 28, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Shany Danieli
Princeton University
Revelations from studies of low mass galaxies: dark matter and galaxy formation on small scales
The number densities, structures, and internal dynamics of low-mass galaxies provide some of the most interesting clues to the nature of dark matter and the theory of galaxy formation on small scales. Up until recently, our understanding of low-mass galaxies has largely been informed by observations of dwarf galaxies that orbit our Milky Way galaxy. I will present novel observational efforts that now enable the discovery of such low surface brightness galaxies beyond our local galactic neighborhood. I will discuss some of the follow-up observations of these extragalactic low-mass galaxies, focusing on their dark matter content and intriguing globular cluster populations, revealing significant diversity and new astrophysical puzzles. I will conclude by discussing ongoing surveys that will be essential in mapping the census and properties of the general population of low-mass galaxies.
March 7, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Melissa Ness
Columbia University
To Be Determined
March 21, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Alyson Brooks
Rutgers University
To Be Determined
March 28, 2023 Tuesday 2:00 PM
+
726
Broadway, 1067
Center for Quantum Phenomena Seminars
(
cqp)
Michael Levin
University of Chicago
TBA
April 4, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Raffaella Margutti
UC Berkeley
To be determined
April 25, 2023 Tuesday 2:00 PM
+
726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Maya Fishbach
University of Toronto
To Be Determined
