The 19th Annual Pappalardo Fellowships in Physics Symposium

via Zoom
Wednesdays, 12:00 – 1:00 PM
April 21 and 28; May 5, 12 and 19, 2021

Five members of the Department’s premier postdoctoral fellowship program, the Pappalardo Fellowships in Physics, will present highlights from their independent research projects. All talks will be especially designed for the enjoyment of all members of the MIT physics community.

In order of appearance:


SCHEDULE OF SPEAKERS

4/21:  Katelin Schutz, 2019-2020 Pappalardo Fellow; 2020 NASA Einstein Fellow
Introductory remarks: Tracy Slatyer, Jerrold R. Zacharias Career Development Associate Professor of Physics

“Making Dark Matter Out of Light”

Dark matter could be a “thermal-ish” relic of freeze-in, where the dark matter is produced by extremely feeble interactions with Standard Model particles dominantly at low temperatures.

In this talk, I will discuss how sub-MeV dark matter can be made through freeze-in, accounting for a dominant channel where the dark matter gets produced by the decay of plasmons–photons that have an in-medium mass in the primordial plasma of our Universe. 

I will also explain how the resulting non-thermal dark matter velocity distribution can impact cosmological observables.

4/28: Anna-Christina Eilers, 2019-2022 NASA Hubble Fellow; 2022-2024 Pappalardo Fellow
Introductory remarks: Robert Simcoe, Francis L. Friedman Professor of Physics; Director, MIT Kavli Institute for Astrophysics and Space Research

“The Formation and Growth of Supermassive Black Holes”

The existence of luminous quasars hosting supermassive black holes within the first billion years of cosmic history challenges our understanding of black hole growth. An important piece of the puzzle is the lifetime of quasars–the time that galaxies shine as active quasars and during which the bulk of the black hole growth occurs–but to date its value remains uncertain by several orders of magnitude. 

I will present a new method to obtain constraints on the lifetime of quasars based on the sizes of ionized regions around quasars known as proximity zones. These proximity zones act as a “quasar clock” and enable us to study the co-evolution of supermassive black holes and their host galaxies from a new perspective.

Surprisingly, our results indicate that black holes can grow several orders of magnitude faster than previously thought, which provides a potential solution to the long-standing puzzle of the rapid black hole growth and new insights into galaxy evolution across cosmic time. 

5/5: Rachel Carr, 2016-2018, 2020-2021 Pappalardo Fellow
Introductory remarks: Janet Conrad, Professor of Physics

“Chasing Anomalies with Reactor Neutrinos”

Nuclear reactors are the brightest sources of neutrinos on earth. Although built for quite different purposes, reactors have delivered a host of surprises, discoveries, and controversies in neutrino physics. 

In the last decade, one intriguing anomaly launched a search for a new type of neutrino even more weakly interacting than the known types. That prize has not yet turned up, but the search is yielding other new facts and perhaps an unconventional nuclear technology. 

Six decades after the first quixotic–and ultimately successful–quest for neutrino signals at a reactor, the chase continues.

5/12: Nicholas Kern, 2020-2023 Pappalardo Fellow
Introductory remarks: Jacqueline Hewitt, Julius A. Stratton Professor in Electrical Engineering and Physics

“Ushering in a New Era for High Redshift Astrophysics and Cosmology with the 21 cm Line​”

The next generation of large-scale cosmological surveys will use hydrogen, the most abundant baryonic species, and its 21-cm spin flip transition to systematically probe the cosmic web from the present day all the way back to the birth of the first stars and galaxies.

This will come from a new class of radio telescopes that have injected fresh energy into low-frequency radio astronomy. Such experiments will open an unprecedented window into high redshift galaxy formation physics, directly constraining the growth and spectral properties of the first stars and galaxies.

They will also present new stress tests of the cosmological standard model, and place novel constraints on the expansion history of the universe. However, in order to achieve these scientific goals, a revolution in precision radio data analysis is required in order to mitigate the giant levels of astrophysical and terrestrial contaminants.

In this talk, I will discuss the potential of the 21 cm line as a powerful probe of cosmology and astrophysics, and the promising work currently underway to detect the cosmological 21 cm signal. While I will touch on a variety of science drivers, I will focus mainly on the efforts to use the 21 cm line as a tool to map out the density, ionization, and temperature state of intergalactic gas during the Epoch of Reionization: the era marking the formation of the first stars and galaxies in the universe.

5/19: Hoi Chun “Adrian” Po, Theoretical Condensed Matter Physics
Introductory remarks: Liang Fu, Lawrence C. (1944) and Sarah W. Biedenharn Career Development Associate Professor of Physics

“Topology at the Corner of the Table”

The influx of topological ideas in the past two decades has completely changed the way we think about materials.

In this talk, we will discuss how the revolution reaches all the way to something we see and even taste every single day: sodium chloride, commonly known as table salt.

We will show that an unnoticed topological aspect of the rock salt structure implies it is an example of the recently introduced notion of higher-order multipole insulators.

As a consequence, the corners of salt crystals are sprinkled with fractions of electrons, which also form part of our daily meals. Bon appétit!


Past Symposia

  • Prof. Jeff Gore, Latham Family Career Development Assistant Professor of Physics
    Introductory Remarks
  • Dr. Taritree Wongjirad, 2014–17 Pappalardo Fellow
    (Experimental Nuclear and Particle Physics)
    “Searching for Neutrino-less Double Beta Decay Using Quantum Dot Nanoparticles”
  • Dr. Inti Sodemann, 2014–17 Pappalardo Fellow
    (Hard Condensed Matter Theory)
    “The Nature of Spin Superfluidity and its Potential Uses”
  • Dr. Meng Su,  2012–15 Pappalardo Fellow
    (Theoretical Astrophysics)
    “From Space to the Tibet Plateau: Probing the Mystery of the Universe in Gamma Ray and Microwave”
  • Dr. Benjamin Safdi, 2014–17 Pappalardo Fellow
    (Theoretical High Energy Physics)
    “Directional Antineutrino Detection”
  • Dr. Yoav Lahini,  2012–15 Pappalardo Fellow
    (Experimental Soft Condensed Matter & Biophysics)
    Towards Optical Measurements of Virus Self-Assembly: How Does a Virus Grow?
  • Prof. Peter Fisher, Head, Department of Physics
    Introductory Remarks
  • Dr. Robert Penna, 2013–16 Pappalardo Fellow
    (Theoretical Astrophysics)
    “Spinning Black Holes”
  • Dr. Jeongwan Haah, 2013–16 Pappalardo Fellow
    (Quantum Information Theory)
    “Protecting Quantum Information”
  • Dr. Inna Vishik,  2013–16 Pappalardo Fellow
    (Experimental Condensed Matter)
    “Adventures in Unconventional Superconductivity”
  • Dr. Guy Bunin, 2013–16 Pappalardo Fellow
    (Biophysics & Non-equilibrium Statistical Mechanics)
    “From Symmetries to Probabilities”
  • Dr. Joshua Spitz,  2011–14 Pappalardo Fellow
    (Experimental Nuclear and Particle Physics)
    “Testing Einstein with Neutrinos”
  • Prof. Marin Soljačić, 2008 MacArthur Fellow; 2000-03 Pappalardo Fellow
    (Condensed Matter Theory)
    Introductory Remarks
  • Dr. David Hsieh, 2009–12 Pappalardo Fellow
    (Condensed Matter Experiment)
    “A New Generation of Insulators for the Electronics Future”
  • Dr. Paul Chesler, 2009–12 Pappalardo Fellow
    (Nuclear & Particle Theory)
    “Applied String Theory: from Gravitational Collapse to Heavy Ion Collisions”
  • Dr. Paola Rebusco, 2007–10 Pappalardo Fellow
    (Theoretical Astrophysics)
    “Astronomers-to-be at MIT”
  • Dr. Yusuke Nishida, 2008–11 Pappalardo Fellow
    (Nuclear & Particle Theory)
    “Universal Physics with Ultracold Atoms”
  • Dr. Jeff Gore, 2007–10 Pappalardo Fellow
    (Biophysics)
    “Is Evolution Reversible?”
  • Prof. Ed Bertschinger, Professor of Physics and Former Head, Department of Physics
    Introductory Remarks
  • Dr. David Tong, 2001-2004 Pappalardo Fellow
    (String Theory)
    “Is String Theory Right or is It Just Useful?”
  • Dr. Robert Simcoe, 2003-2006 Pappalardo Fellow
    (Experimental Astrophysics)
    “Playing with FIRE: The Edge of the Universe as seen from Magellan”
  • Dr. Jocelyn Monroe, 2006-2009 Pappalardo Fellow
    (Dark Matter and Neutrino Physics)
    “Particle Physics at the Dark Frontier”
  • Dr. Michael Fogler, 2000-2003 Pappalardo Fellow
    (Condensed Matter Theory)
    “Graphene Twist and Rock-n-Roll”
  • Dr. Henriette Elvang, 2005-2008 Pappalardo Fellow
    (String Theory)
    “Recent Advances in Amplitude Calculations and Their Applications”