Summary - Google Drive


1	Date	1/22/2021
2	Name	Dan Hooper
3	Affiliation	Fermilab/University of Chicago
4	Home Page
5	Colloquium Title	Black Holes in the Early Universe
6	Abstract	Cosmology textbooks typically assume that the early universe was dominated by relativistic particles. But if even a relatively small number of black holes were created after inflation, they would make up an increasingly large fraction of the total energy density as space expands. I’ll argue that it is well-motivated to scenarios in which the early universe included an era in which low-mass (<10^8 grams) primordial black holes dominated the total energy density. Within this context, I’ll discuss Hawking radiation as a mechanism to produce both dark radiation and dark matter. I’ll also talk about the possibility that these black holes may have undergone mergers before evaporating, leading to potentially detectable gravitational waves signals, and to the production of a “hot graviton background”.
7	Host	Graduate Student Association
8	Date	1/29/2021
9	Name	Brian Odom
10	Affiliation	Northwestern University
11	Home Page	https://faculty.wcas.northwestern.edu/brian-odom/index.html
12	Colloquium Title	Adding Molecules to the Quantum Toolkit
13	Abstract	Development of laser-based techniques to cool and manipulate trapped atoms led to a quantum revolution, with applications ranging from creation of novel phases of matter to realization of new tools for navigation and timekeeping. Compared with atoms, the rich internal structure of molecules offers additional potential. However, obtaining control over the rotational quantum state of trapped molecules, a prerequisite for most applications, has presented a significant challenge because of the large number of internal states. I will discuss techniques we have developed to optically cool rotations of trapped molecular ions using a single broadband laser. I will also discuss applications including searches for new physics, probing quantum structure near the bond breaking point, quantum information processing, and blackbody thermometry.
14	Host	Graduate Student Association
15	Date	2/26/2021
16	Name	Jesse Thaler
17	Affiliation	MIT
18	Home Page	http://www.jthaler.net/
19	Colloquium Title	Collision Course: Particle Physics meets Machine Learning
20	Abstract	Modern machine learning has had an outsized impact on many scientific fields, and particle physics is no exception. What is special about particle physics, though, is the vast amount of theoretical and experimental knowledge that we already have about many problems in the field. In this colloquium, I present two cases studies involving quantum chromodynamics (QCD) at the Large Hadron Collider (LHC), highlighting the fascinating interplay between theoretical principles and machine learning strategies. First, by cataloging the space of all possible QCD measurements, we (re)discovered technology relevant for self-driving cars. Second, by quantifying the similarity between two LHC collisions, we unlocked a class of nonparametric machine learning techniques based on optimal transport. In addition to providing new quantitative insights into QCD, these techniques enable new ways to visualize data from the LHC.
21	Host	Graduate Student Association
22	Date	4/16/2021
23	Name	Xie Chen
24	Affiliation	California Institute of Technology
25	Home Page
26	Colloquium Title	Fracton order: from quantum hard drive to foliated manifold
27	Abstract	One major open problem in quantum information theory is how to build a quantum hard drive, i.e. a quantum system that can store quantum information reliably for a long time without active error correction. No completely satisfying solution to this problem has been found, but in the search a whole new class of quantum many-body models have been discovered with exotic properties never seen before. This new class of models, dubbed the “fracton” models, have point excitations that cannot move freely, a robust ground state degeneracy that increases with system size, and slow dynamics even without any disorder. In this talk, I will introduce some of the most important fracton models and present a systematic framework for characterizing their universal properties. By realizing that the properties depend on the foliation structure of the underlying manifold, we reveal the hidden equivalence relation between many seemingly different models and identify the direction of search for new features.
28	Host	Graduate Student Association
29	Date	4/23/2021
30	Name	Jimena Canales
31	Affiliation	86 South St. 5A, Boston, MA 02111
32	Home Page	https://www.jimenacanales.org/
33	Colloquium Title	Science and the History of Nonexistents
34	Abstract	What does not or does not yet exist plays a predominant role in science and technology. Discovery involves the bringing into existence of the new. As scientists search for answers and solutions, they are often confronted with problems and paradoxes that seems to escape from the realm of reason. The cause of such mischief is often anthropomorphized, called a demon, and given the last name of famous scientists, such as Descartes, Laplace, and Maxwell. The antechamber of discovery is not as, as is frequently thought, a an inscrutable “private art” marked by a punctual “Eureka!” moment. It is a rich cultural, social, economic and political space were sought-after imaginary perpetrators have recognizable characteristics that have remained fairly constant throughout many centuries. A study of the half-empty glass of scientific research reveals certain patterns in the search terms that drive important discoveries in key areas of science.
35	Host	Graduate Student Association


1	Date	9/10/2021
2	Name	Jonathan Lunine
3	Affiliation	Cornell University
4	Home Page	https://research.cornell.edu/researchers/jonathan-i-lunine
5	Colloquium Title	The search for life in the outer solar system
6	Abstract	The Cassini and Galileo missions to Jupiter and Saturn have discovered moons with liquid water beneath icy crusts, and in one case seas of methane and ethane. New generations of instruments for spaceflight permit us to go back to these moons, determine if they can support life, and even test whether life exists there under the ice. I will describe these exciting planned and proposed missions.
7	Host	Graduate Student Association
8	Date	10/22/2021
9	Name	Alysia Marino
10	Affiliation	University of Colorado Boulder
11	Home Page
12	Colloquium Title	Discovering Neutrino Properties with Long-Baseline Beams
13	Abstract	Neutrinos are fundamental particles with no electric charge and as-yet-unmeasured masses, allowing them to travel unimpeded through enormous amounts of material. Despite their elusiveness, a lot of compelling evidence shows that neutrinos have non-zero masses and change from one flavor to another. Intense neutrino beams generated by particle accelerators are now being used in order to more precisely probe the physics of neutrino masses and mixing. As an example of a neutrino beam project, it will focus on the Tokai-to-Kamioka (T2K) experiment, which creates a beam of muon neutrinos at J-PARC on the east coast of Japan. With two neutrino detectors, one located near the origin of the beam, and another located 295 km away, T2K has seen the disappearance of muon neutrinos and the appearance of electron neutrinos. More recently T2K has uncovered hints that neutrinos and their anti-particles might not oscillate with the same probabilities, an indication of CP violation.
14	Host	Graduate Student Association