.Mitchell Institute (MIST) Events
Spring 2022
January 19, 2022
4:00 pm – 5:00 pm (CDT)
Manifesting the Imprints of Elastic and Exothermic Scatterings Among Dark Matter Particles in Astrophysical/Cosmological Observations
Speaker: Heejung Kim (Institute for Basic Science)Host: Doojin Kim
In this talk, I will give an overview of how elastic and exothermic scatterings among dark matter particles give rise to distinctive features in late-time structure formation. I will explain how astrophysical observations on the structures of galaxies can probe such unique features, and discuss how the observations can help [...]
Pathways to Discovery in Astronomy and Astrophysics in the 2020’s
Speaker: Rob Kennicutt (Texas A&M University)Host: Stephanie Ho
Recently the National Academy of Sciences completed a comprehensive decadal survey of research opportunities, strategic opportunities, and the state of the profession in astronomy and astrophysics. The survey involved more than 130 members of the survey committee and its 13 sub-panels, and was informed by more than 860 white papers [...]
Automorphic Spectra and the Conformal Bootstrap
Speaker: Sridip Pal (Institute for Advanced Study)Host: Anindya Sengupta
We point out that the spectral geometry of hyperbolic manifolds provides a remarkably precise model of the modern conformal bootstrap. As an application, we use conformal bootstrap techniques to derive rigorous computer-assisted upper bounds on the lowest positive eigenvalue **\lambda_1(X)** of the Laplace-Beltrami operator on closed hyperbolic surfaces and 2-orbifolds [...]
The Geometric SMEFT Description of Curved Higgs Field Space(s)
Speaker: Mike Trott (Niels Bohr Institute)Host: Doojin Kim
In recent years, the effective field theory approach to the Standard Model, the SMEFT, has been used to study LHC data with ever increasing theoretical precision and sophistication. However, the complexity of this theory lead to several barriers to substantial theoretical progress. In particular, the explosion in the number of parameters in the SMEFT as [...]
January 31, 2022
2:00 pm – 3:00 pm (CDT)
Symmetries and Anomalies at the IR Fixed Point of Gravity
Speaker: Kurt Hinterbichler (Case Western Reserve University)Host: Daniel Butter
I will discuss symmetries that arise at the infrared fixed point of the RG flow of Einstein gravity, including conformal vs. scale invariance in various dimensions, as well as 1-form generalized global symmetries and new anomalies that arise among them.
January 31, 2022
11:30 am – 12:30 pm (CDT)
Exploding Stars and Catastrophic Collisions
Speaker: Kate Maguire (Trinity College Dublin)Host: Stephanie Ho
Supernovae (and stellar collisions) are the incredibly luminous (and not so luminous) deaths of stars that play a vital role in chemical enrichment, galaxy feedback mechanisms, and our understanding of stellar evolution. In particular, Type Ia supernovae, the explosions of white dwarfs in binary systems, are vital for constraining the [...]Aspects of the Black Hole/String Transition
Speaker: Yiming Chen (Princeton University)Host: Haoyu Zhang
It has long been speculated that a black hole in string theory turns into highly excited strings close to the Hagedorn temperature. Gravitational attraction pulls different parts of the string together, forming a star-like configuration. In this talk, I will review the properties of a concrete solution of this kind, [...]
February 7, 2022
11:30 am – 12:30 pm (CDT)
The Universe from the Edge of the Dark Matter Halo
Speaker: Susmita Adhikari (University of Chicago)Host: Stephanie Ho
Understanding the formation and evolution of non-linear structure in the universe can shed light on some of the most fundamental questions in Cosmology. The splashback radius has emerged as probe of physics in the interface of galaxy formation and Cosmology. It forms the edge of the orbiting region of a [...]Strong Cosmic Censorship Versus Λ
Speaker: Mihalis Dafermos (University of Cambridge & Princeton University)Host: Christopher Pope
The strong cosmic censorship conjecture is a fundamental open problem in classical general relativity, first put forth by Roger Penrose in the early 70s. This is essentially the question of whether general relativity is a deterministic theory. Perhaps the most exciting arena where the validity of the conjecture is challenged [...]
Spectroscopic Vision: Tracing the Formation and Evolution of Massive Galaxies Through Cosmic Time
Speaker: Rachel Bezanson (University of Pittsburgh)Host: Jonelle Walsh
Massive galaxies, though relatively rare in number, host most of the stars in the Universe and deep in their cores harbor the most extreme supermassive black holes. Today massive galaxies are red and dead ellipticals with little ongoing star formation or organized rotation; naturally they were expected to be relics [...]
February 21, 2022
2:00 pm – 3:00 pm (CDT)
Bootstrap of the KLT Double-Copy
Speaker: Henriette Elvang (University of Michigan)Host: Christopher Pope
In field theory, the "double copy" can be thought of as a multiplicative map between tree amplitudes of two field theories into tree amplitudes of another theory. The origin of the map is string theory, but from a bottom-up Effective Field Theory approach, a natural question is if there exists other [...]
February 28, 2022
2:00 pm – 3:00 pm (CDT)
Emergent Cosmology from Matrix Theory
Speaker: Robert Brandenberger (McGill University)Host: Ergin Sezgin/Ali Kaya
I will argue that standard Effective Field Theory techniques are inapplicable to describe the very early universe, and that we hence need to turn to a non-perturbative approach. The BFSS (Banks, Fischler, Shenker and Susskind) matrix model is a proposed non-perturbative definition of superstring theory. It is a quantum mechanical [...]
February 28, 2022
11:30 am – 12:30 pm (CDT)
Do Some SMBH in Nearby Galaxies Come in Pairs? – An Observer’s Tale
Speaker: Sabine Thater (University of Vienna)Host: Jonelle Walsh
The formation of supermassive black holes (MBH) is thought to be tightly linked to the formation and growth of their host galaxies. While it is difficult to infer information about MBHs, galaxy evolution often leaves an imprint on the host galaxy properties. One of those properties is that the most [...]Hidden Symmetries and Static Response of Black Holes
Speaker: Riccardo Penco (Carnegie Mellon University)Host: Christopher Pope
Black holes in 4D General Relativity have the remarkable property that they lack any form of static linear response. At length scales much larger than the Schwarzschild radius, where black holes can be described as point particles, their linear response is captured by an infinite number of Wilson coefficients in [...]Double Neutron Star Origins: Towards Multiscale Multiphysics Modeling for a Multimessenger Puzzle
Speaker: Miguel Holgado (Carnegie Mellon University )Host: Jonelle Walsh
Gravitational-wave observations of merging black holes and merging neutron stars have significantly impacted our understanding of the formation and evolution of compact-object binaries. One of the most pressing uncertainties in how double neutron stars form is the common-envelope phase, whereby a neutron star inspirals within the envelope of a massive [...]From Mini to Micro: Zooming in on New Physics Interpretations of the MiniBooNE Excess at the MicroBooNE Experiment
Speaker: Matheus Hostert (Perimeter Institute & University of Minnesota)Host: Doojin Kim
The MicroBooNE experiment has recently tested a few interpretations of the MiniBooNE excess. I will discuss the impact of MicroBooNE's searches on new physics models and show that it still does not provide a definitive test of the MiniBooNE anomaly. I will also discuss the broader landscape of models with MeV [...]Extracting all Information from Future Surveys
Speaker: Sultan Hassan (Flatiron Institute)Host: Lucas Macri
Extracting the maximum amount of astrophysical and cosmological information remains a challenge in the current and future reionization surveys. These include, for instance, the recently launched NASA’s James Webb Space Telescope (JWST), the Euclid, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), the [...]
March 21, 2022
11:30 am – 12:30 pm (CDT)
The Origins of Black Holes and Their Effect on Their Host Galaxies
Speaker: Mallory Molina (Montana State University)Host: Lucas Macri
Active supermassive black holes have a significant and lasting impact on the evolution of their host galaxy, but their origins remain a mystery. Meanwhile massive black holes in dwarf galaxies can help constrain the properties of the initial black hole seeds but their impact on their host galaxies is not [...]Constraining Couplings of End-of-the-World Branes
Speaker: Dominik Neuenfeld (Perimeter Institute)Host: Daniel Butter
End-of-the-world (ETW) branes are used in shedding light on Page curve computations, model black hole microstates, and embedding cosmology into holography. I will review braneworld constructions and discuss a mechanism for how the effective theory on the brane arises from a reorganization of UV data. Oftentimes it is useful (as [...]
March 25, 2022
1:00 pm – 2:00 pm (CDT)
News on Supermembrane Theory
Speaker: Hermann Nicolai (Albert Einstein Institute)Host: Christopher Pope
The maximally supersymmetric supermembrane theory in space-time dimension D = 11 is a model ‘beyond’ string theory that incorporates D = 11 supergravity as a `low energy limit', and is thus a candidate theory for a non-perturbative formulation of superstring theory. In this talk I will review some basic features, [...]Understanding Planetary Evolution with TESS
Speaker: Joey Rodriguez (Michigan State University)Host: Stephanie Ho
The success of transit and RV surveys have shifted the exoplanet field from pure discovery to a combination of discovery, demographic analysis, and detailed characterization, especially for exoplanet atmospheres. However, even with nearly 5000 exoplanets known, we are still working to understand their origins and evolutionary mechanisms. Using data from NASA’s TESS [...]Machine Learned Collider Observables, Noise-Aware Qubit Assignment
Speaker: Prasanth Shyamsundar (Fermilab)Host: Doojin Kim
In the first part of this talk, I will describe a new machine learning technique to learn sensitive event observables to analyze collider data. In the second part, I will discuss a technique for mitigating the effect of hardware noise on quantum computations in present day quantum hardware.The Physical Origin of the Death of Massive Galaxies in the Local Universe
Speaker: Chengpeng Zhang (Texas A&M University)Host: Stephanie Ho
Local galaxies can be broadly divided into star-forming and quiescent galaxies. The physical mechanism responsible for star formation quenching is one of the most debated open questions for understanding galaxy evolution. As the fuel of star formation, the cold gas content in galaxies will provide direct observational evidence of how [...]BPS and Near-BPS Black Holes in AdS_5 and Their Spectrum in N=4 SYM
Speaker: Luca Iliesiu (Stanford University)Host: Aritra Saha
We study quantum corrections in the gravitational path integral around nearly 1/16-BPS black holes in asymptotically AdS5 × S 5 space, dual to heavy states in 4D N = 4 super YangMills. The analysis provides a gravitational explanation of why 1/16-BPS black holes exhibit an exact degeneracy at large N [...]The Hunt for Gluonic ALPs
Speaker: Zhen Liu (University of Minnesota)Host: Doojin Kim
Axion coupling to gluons is the defining property that connects it to the Strong CP puzzle. People have recently started to consider heavier axions, often dubbed Axion-Like-Particles (ALPs), as a generic EFT for pseudo-scalars. However, the effects have mostly been focused on other couplings as they are much easier to calculate [...]Asymptotic Einstein’s Equations and Celestial Symmetries
Speaker: Daniele Pranzetti (Perimeter Institute)Host: Daniel Butter
I will first show how the leading Einstein equations in a large-r expansion around null infinity can be derived and recast in a compact form by relying uniquely on the transformation properties under the corner symmetry group at scri, the so-called Weyl BMS group. In addition to the to spin-0 and [...]Beyond the WIMP Paradigm
Speaker: Wei Xue (University of Florida)Host: Doojin Kim
Weakly-interacting massive particle (WIMP) has been the leading paradigm of dark matter for decades. Still, experimental searches for non-gravitational signatures of WIMPs have not found any positive evidence yet. It motivates us to think about new search strategies and novel dark matter models. My talk consists of the two directions [...]Complex Saddles and Euclidean Wormholes in the Lorentzian Path Integral
Speaker: Gary Shiu (University of Wisconsin-Madison)Host: Ergin Sezgin
We study complex saddles of the Lorentzian path integral for 4D axion gravity and its dual description in terms of a 3-form flux, which include the Giddings-Strominger Euclidean wormhole. Transition amplitudes are computed using the Lorentzian path integral and with the help of Picard-Lefschetz theory. The number and nature of saddles is shown to [...]A Dynamics-Based Density Profile for Dark Matter Halos
Speaker: Benedikt Diemer (University of Maryland)Host: Jonelle Walsh
We now know that the density profiles of dark matter haloes carry signatures of their dynamical state and even of the nature of dark matter. Some of the most interesting signals reside at large radii (around the virial radius and beyond), which have recently become observationally accessible via satellite distributions [...]Dark Solar Wind
Speaker: Jae Hyeok Chang (University of Maryland)Host: Doojin Kim
I will talk about light dark sector particles that weakly couple to ordinary particles but strongly couple to each other. Such particles can be produced from the Sun and fully thermalized with its own temperature. The resulting dark fluid accelerates under its own thermal pressure and attains a highly relativistic [...]