September 23, 2021 Thursday 4:00 PM
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Hybrid: 726 Bdwy 940 and Zoom
Physics Colloquia
(
colloquia)
Gordon Baym
University of Illinois Urbana-Champaign
The Golden Age of Neutron Stars
Neutron stars were first posited in the early thirties, and discovered as pulsars in the late sixties; however we are only recently beginning to understand the matter they contain. I will describe the ongoing development of a consistent picture of the liquid interiors of neutron stars, now driven by ever increasing observations as well as theoretical advances. These include in particular observations of three heavy neutron stars of about 2.0 solar masses and higher; ongoing simultaneous inferences of masses and radii of neutron stars by the NICER telescope; and past and future observations of binary neutron star mergers, through gravitational waves as well as across the electromagnetic spectrum. Theoretically an understanding is emerging in QCD of how nuclear matter can turn into deconfined quark matter in the interior, and be capable of supporting heavy neutron stars, which I will illustrate with a discussion of modern quark-hadron crossover equations of state.
September 27, 2021 Monday 9:30 AM
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Hybrid: 726 Bdwy 871 and Zoom
Soft Condensed Matter Seminars
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csmr)
CSMR Monday Morning Seminar
Xinhang Shen (Pine Lab)
Buming Guo (Chaikin Lab)
Zoom link: https://nyu.zoom.us/j/97877399053
September 28, 2021 Tuesday 2:00 PM
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zoom
Astrophysics and Relativity Seminars
(
astro)
Jenny Greene
Princeton University
TBA
TBA
September 29, 2021 Wednesday 10:00 AM
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Zoom: https://nyu.zoom.us/j/93506405032
Soft Condensed Matter Seminars
(
csmr)
Alberto Fernandez-Nieves
University of Barcelona
Physics of Fire Ant Collectives
September 30, 2021 Thursday 4:00 PM
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Zoom
Physics Colloquia
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colloquia)
Kate Grier
University of Arizona
Quasars and Supermassive Black Holes: Uncovering Mysteries with Variability and Reverberation Mapping
Supermassive black holes, with masses that range from tens of thousands to billions of times the mass of our Sun, are thought to be present in nearly every galaxy in the Universe and may affect the growth and evolution of these galaxies. To understand how supermassive black holes interact with their host galaxies, we require accurate measurements of supermassive black hole masses in galaxies across the entire universe, as well as an understanding of their physical environments. We obtain this information by observing objects called active galactic nuclei, or quasars, which have supermassive black holes with large amounts of matter falling into them. These sources are highly variable, and we can use their variability to both measure their masses and learn about the physical environment very close to the black holes. We do this by examining the time delays between continuum flux variations and the response of distant gas as it reprocesses the ionizing radiation into emission lines which thus seem to “reverberate,” echoing the continuum variations; this technique is called reverberation mapping. In my talk, I will discuss supermassive black holes, active galactic nuclei/quasars, and the use of time variability -- primarily the technique of reverberation mapping -- to learn about these phenomena. I will focus specifically on my recent and planned work on large-scale reverberation-mapping projects using data from large surveys such as the Sloan Digital Sky Survey, which have allowed us to investigate large numbers of quasars at much greater distances than ever before.
October 4, 2021 Monday 12:30 PM
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726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
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ccpp)
CCPP Brown Bag
David W. Hogg
New York University
Einstein summation notation and machine learning
October 5, 2021 Tuesday 2:00 PM
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726
Broadway, CQP room #1067
Center for Quantum Phenomena Seminars
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cqp)
Vladimir Manucharyan
University of Maryland
TBA
October 6, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Fei Yan
Rutgers
HEP Seminar
October 7, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Javad Shabani
New York University
TBA
October 8, 2021 Friday 11:00 AM
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Hybrid: 726 Bdwy TBD and Zoom
Physics Colloquia
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colloquia)
Ahmed Almheiri
Institute for Advanced Study
TBA
October 12, 2021 Tuesday 2:00 PM
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726
Broadway, CQP room #1067
Center for Quantum Phenomena Seminars
(
cqp)
Carmen Rubio-Verdú
Columbia University
TBA
October 12, 2021 Tuesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Colin Hill
Columbia University & CCA
Searching for New Physics in the Universes Oldest Light with the Atacama Cosmology Telescope
I will discuss recent and ongoing work focused on attempts to restore concordance amongst cosmological data sets, motivated by discrepancies amongst some measurements of the cosmic expansion rate H_0 and the matter clustering amplitude S_8. Particular attention will be paid to models invoking new physics at or prior to recombination, including quasi-accelerating early dark energy models and small-scale baryon-clumping scenarios e.g., due to primordial magnetic fields. In particular, I will discuss constraints on these models derived using the latest data from the Atacama Cosmology Telescope ACT. I will conclude with a look ahead to forthcoming CMB measurements from ACT, which will provide a powerful test of these models in the low-noise, high-resolution regime.
October 14, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
(
colloquia)
Esra Bulbul
Harvard University
TBA
October 18, 2021 Monday 12:30 PM
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726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
(
ccpp)
CCPP Brown Bag
Yifan Wang
New York University
October 19, 2021 Tuesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Kevin Hand
Jet Propulsion Lab
Alien Oceans on Earth and Beyond
Where is the best place to find living life beyond Earth? It may be that the small, ice-covered moons of Jupiter and Saturn harbor some of the most habitable real estate in our Solar System. Life loves liquid water and these moons have lots of it.
These alien oceans of the outer solar system have likely persisted for much of the history of the solar system and as a result they are highly compelling targets in our search for life beyond Earth. Within these oceans may reside a second origin of life itself, and the answer to whether or not we live in a biological universe, or one in which life on Earth represents a biological singularity. Dr. Hand will explain the science behind why we think we know these oceans exist and what we know about the conditions on these worlds. He will focus on Jupiter’s moon Europa, which is a top priority for future missions. Dr. Hand will also detail how the exploration of Earth’s ocean is helping to guide our understanding of the potential habitability of worlds like Europa.
October 19, 2021 Tuesday 2:00 PM
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726
Broadway, CQP room #1067
Center for Quantum Phenomena Seminars
(
cqp)
Yassine Quessab
NYU
TBA
October 21, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Lance Dixon
Stanford University
Scattering Amplitudes from LHC to LIGO and Beyond
LIGO, VIRGO, and other gravitational wave interferometers are ushering
in a new era of astrophysics, where the messenger is the graviton.
The LHC provides the highest energy particle collisions available
in the laboratory, searching for new particles and new interactions.
These two arenas seem totally unrelated: One is governed by classical gravity,
the other by non-Abelian gauge theories such as quantum chromodynamics.
However, these two theories are secretly related by a "double copy":
graviton scattering amplitudes are essentially the square of gluon amplitudes.
Along with modern scattering amplitude methods, which have led to more precise
predictions for LHC processes, the double copy has enabled the study
of ultraviolet divergences in quantum (super)gravity to high loop orders.
The same tools are now being applied to classical gravity, in regimes
relevant for improving predictions for gravitational waveforms for
inspiralling black holes and neutron stars.
October 26, 2021 Tuesday 2:00 PM
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726
Broadway, CQP room #1067
Center for Quantum Phenomena Seminars
(
cqp)
Tianci Zhou
MIT
TBA
October 27, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
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hep)
Mark Mezei
Stony Brook
HEP Seminar
October 28, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Andrea Liu
University of Pennsylvania
TBA
November 3, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Pouya Asadi
MIT
HEP Seminar
November 4, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Cristina Marchetti
University of California Santa Barbara
TBA
November 9, 2021 Tuesday 2:00 PM
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726
Broadway, CQP room #1067
Center for Quantum Phenomena Seminars
(
cqp)
Mingzhong Wu
Colorado State University
Topological Surface States in Dirac Semimetal α-Sn
Topological Dirac semimetals represent a relatively newly-discovered topological quantum phase. In comparison with other topological Dirac semimetals, α-Sn is much more attractive because (1) it is a single-element material and is therefore relatively easy to grow, and (2) it can transform to other topological phases, such as a topological insulator or a Weyl semimetal, under certain strain or field conditions. This talk will report on recent experimental work on topological surface states in Dirac semimetal α-Sn thin films. The talk will consist of three parts. Part I will focus on magnetoresistance in α-Sn thin films that scales linearly with both magnetic and electric fields [1]. Such bilinear magneto-electric resistance results from the spin-momentum locking of the topological surface states in α-Sn films. Part II will be on large damping enhancement in a ferromagnetic thin film due to topological surface states in an adjacent α-Sn thin film [2]. It will be shown that an α-Sn film separated from a NiFe film by a Ag spacer can cause an extra damping in NiFe that is three times bigger than the intrinsic damping. Part III will report on current-induced magnetization switching in an α-Sn/Ag/CoFeB trilayer [3]. Thanks to the surface states in α-Sn, the magnetization in CoFeB can be switched by a charge current at room temperature, without an external magnetic field. The data show that the switching is driven by topological surface states in α-Sn, rather than spin-orbit coupling in the bulk of α-Sn or current-produced heating. Taken together, these results suggest that, like topological insulators, the topological Dirac semimetal α-Sn may have promising applications in spintronics.
REFERENCES:
[1] “Large magneto-electric resistance in the topological Dirac semimetal α-Sn,” Yuejie Zhang, Vijaysankar Kalappattil, Chuanpu Liu, Steven S.-L.
Zhang, Jinjun Ding, Uppalaiah Erugu, Jifa Tian, Jinke Tang, and Mingzhong Wu, submitted (2021).
[2] “Large damping enhancement in Dirac-semimetal – ferromagnetic-metal layered structures caused by topological surface states,” Jinjun Ding, Chuanpu Liu, Yuejie Zhang, Vijaysankar Kalappattil, Rui Yu, Uppalaiah Erugu, Jinke Tang, Haifeng Ding, Hua Chen, and Mingzhong Wu, Advanced Functional Materials 2021, 2008411 (2021).
[3] “Switching of a magnet by spin-orbit torque from a topological Dirac semimetal,” Jinjun Ding, Chuanpu Liu, Vijaysankar Kalappattil, Yuejie Zhang,
Oleksandr Mosendz, Uppalaiah Erugu, Rui Yu, Jifa Tian, August DeMann, Stuart B. Field, Xiaofei Yang, Haifeng Ding, Jinke Tang, Bruce Terris,
Albert Fert, Hua Chen, and Mingzhong Wu, Advanced Materials 2021, 2005909 (2021).
November 10, 2021 Wednesday 11:00 AM
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726
Broadway, 940, CCPP Seminar
Other Center for Cosmology and Particle Physics Events
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ccpp)
Informal Astro Talk
Erin Kado-Fong
Princeton University
Distinguishing formation mechanisms of dwarf galaxies using their intrinsic shapes
November 10, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
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hep)
Sergei Lukyanov
Rutgers
HEP Seminar
November 11, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Paola Cappellaro
Massachusetts Institute of Technology
TBA
November 16, 2021 Tuesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Nico Garavito-Camargo
Flatiron CCA
Implications of the ongoing interaction between the Milky Way and the Large Magellanic Cloud for the CDM paradigm
The ongoing interaction with the Large Magellanic Cloud LMC is revolutionizing our view of the dynamical state of the Milky. The perturbations caused by the LMC open new avenues to test the nature of dark matter. Using results from high-resolution N-body simulations, I will describe the two main perturbations caused by the LMC: the DM wake and the reflex motion. The recent discovery of the stellar wake counterpart of the DM wake opens the opportunity to test the different DM models. Furthermore, I will illustrate how the time-dependent potential of the MW--LMC system complicates efforts to recover the triaxial structure of the halo using the kinematic of the stellar halo. Finally, I will discuss how some current challenges to cold dark matter theory, such as the plane of satellites of the MW, are likely natural consequences of the MW--LMC interaction.
November 17, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
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hep)
Peizhi Du
Stony Brook
HEP Seminar
November 18, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Mohammad Hafezi
University of Maryland
TBA
November 23, 2021 Tuesday 2:00 PM
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zoom
Astrophysics and Relativity Seminars
(
astro)
Kathryn Kreckel
Heidelberg University
TBA
TBA
December 1, 2021 Wednesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
High Energy Physics Seminars
(
hep)
Edoardo Vitagliano
UCLA
HEP Seminar
December 2, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Eva Silverstein
Stanford University
TBA
December 7, 2021 Tuesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
(
astro)
Diana Powell
Harvard/Smithsonian Center for Astrophysics
December 9, 2021 Thursday 9:00 AM
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Flatiron Institute
Other Center for Cosmology and Particle Physics Events
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ccpp)
Gotham Fest
Various Various
Flatiron Institute
Gotham Fest 2021
Further Details TBA. Location: Flatiron Institute
December 9, 2021 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Jason Alicea
Caltech
TBA
December 10, 2021 Friday 9:00 AM
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Flatiron Institute
Other Center for Cosmology and Particle Physics Events
(
ccpp)
Gotham Fest
Various Various
Flatiron Institute
Gotham Fest 2021
Further Details TBA. Location: Flatiron Institute
December 14, 2021 Tuesday 2:00 PM
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726
Broadway, 940, CCPP Seminar
Astrophysics and Relativity Seminars
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astro)
Justin Read
University of Surrey
February 3, 2022 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
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colloquia)
Andrea Young
University of California Santa Barbara
TBA
February 17, 2022 Thursday 4:00 PM
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Zoom
Physics Colloquia
(
colloquia)
David Hsieh
Caltech
TBA
February 24, 2022 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
(
colloquia)
Chanda Prescod-Weinstein
University of New Hampshire
TBA
April 28, 2022 Thursday 4:00 PM
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726
Broadway 940
Physics Colloquia
(
colloquia)
Edward Witten
IAS
TBA
