Dark matter (Astronomy)

Interview with Surjeet Rajendran, Associate Professor of Physics at Johns Hopkins University. He provides an overview of his current research activities with David Kaplan in black hole physics, new short distance forces, and modifications of quantum mechanics, and he shares his reaction on the recent g-2 muon anomaly at Fermilab. Rajendran explains why he identifies as a “speculator” in physics, he recounts his childhood in Chennai, India, and he discusses his grandparents’ communist activism, his Jesuit schooling, and how science offered a refuge for rebellion from these influences. He explains his decision to transfer from the Indian Institute of Technology to Caltech as an undergraduate, where he worked with Alan Weinstein on LIGO. Rajendran discusses his graduate research at Stanford, where KIPAC had just started, and where Savas Dimopoulos supervised his work on PPN parameters and solving the seismic noise problem on atom interferometers for LIGO. He describes his postdoctoral work, first at MIT and then at Johns Hopkins, when he began to collaborate with Kaplan on axion detection and the electroweak hierarchy problem. Rajendran explains the rise and fall of the BICEP project, and his Simons Foundation supported work on CASPEr. He discusses his interest in bouncing cosmology and firewalls in general relativity, and he conveys optimism that LIGO will advance our understanding of black hole information. At the end of the interview, Rajendran reviews his current interests in the Mössbauer effect, and explains how nice it was to win the New Horizons in Physics prize, and he prognosticates on how the interplay between observational and theoretical cosmology will continue to evolve and perhaps resolve fundamental and outstanding questions in the field.

Interview with Murdock Gilchriese, Senior Physicist at Lawrence Berkeley National Lab. He discusses his contribution to the major project, LUX-ZEPLIN (LZ) and the broader search for dark matter, he recounts his parents’ missionary work, and his upbringing in Los Angeles and then in Tucson. Gilchriese describes his early interests in science and his undergraduate experience at the University of Arizona, where he developed is expertise in experimental high energy physics. He discusses his graduate work at SLAC where he worked with Group B headed by David Leith, and he describes his research in hadron spectroscopy. Gilchriese explains his postdoctoral appointment at the University of Pennsylvania sited at Fermilab to do neutrino physics before he accepted his first faculty position at Cornell to help create an e+/e- collider and the CLEO experiment. He discusses the inherent risk of leaving Cornell to work for the SSC project with the central design group, and then as head of the Research Division. Gilchriese describes his subsequent work on the solenoidal detector and his transfer to Berkeley Lab to succeed George Trilling and to join the ATLAS collaboration. He explains the migration of talent and ideas from the SSC to CERN and discusses the research overlap of ATLAS and CMS and how this accelerated the discovery of the Higgs. Gilchriese describes his next interest in getting into cosmology and searching for dark matter as a deep underground science endeavor, and he explains why advances in the field have been so difficult to achieve. At the end of the interview, Gilchriese describes his current work on CMB-S4, his advisory work helping LBNL navigate the pandemic, and he reflects on the key advances in hardware that have pushed experimental physics forward during his career.

The interviewee has not given permission for this interview to be shared at this time. Transcripts will be updated as they become available to the public. For any questions about this policy, please contact [email protected].

The interviewee has not given permission for this interview to be shared at this time. Transcripts will be updated as they become available to the public. For any questions about this policy, please contact [email protected].

Interview with Katherine Freese, Director of the Weinberg Institute for Theoretical Physics, the Jeff and Gail Kodosky Endowed Chair in Physics at UT Austin, and the Director of the Texas Center for Cosmology and Astroparticle Physics (TCCAP). Freese begins the interview with an overview of terminology, such as cosmology, astrophysics, and astroparticle physics and the delineation between these fields. Then she describes her childhood in Bethesda, Maryland where both her parents were scientists. Freese recalls beginning college at age 16, starting at MIT and then transferring to Princeton. She recounts taking time off after her undergraduate studies, before deciding to pursue graduate studies. Freese began grad school at Columbia but switched to the University of Chicago to work on neutrino physics with David Schramm. She discusses her first post-doc at Harvard, working on WIMPs and dark matter, and then her second post-doc at Santa Barbara with Frank Wilczek. Freese then recalls returning to MIT as a professor where she worked with Alan Guth and Josh Frieman on cosmic inflation. She talks about her transition to the University of Michigan and the exciting developments in cosmology at the time, as well as her introduction to dark energy. Freese describes her more recent involvement with NASA’s SPIDER experiment, as well as the honor of being named to the National Academy of Sciences. Freese discusses the amazing opportunity of being the Director at the Nordic Institute for Theoretical Physics and ends the interview with her hopes for the future of cosmology, namely her hope for finding dark matter.

In this interview, Paul Schechter, the William A. M. Burden Professor of Astrophysics, Emeritus, at MIT discusses his time as an undergraduate student at Cornell University under the mentorship of Al Silverman and his involvement working on the Cornell synchrotron, as well as Silverman’s influence on his decision to attend Caltech for graduate school. Schechter discusses his collaboration with Bill Press on the issue of dark matter and the eventual creation of their model, the Extended Press-Schechter. He also details how studying the infall of galaxies toward the Virgo Cluster, and the subsequent paper he contributed to on the topic, were the most exciting part of his time working at the Kitt Peak National Observatory. Schechter describes his later interests in gravitational lensing and his efforts to create higher quality images for Magellan telescopes. Lastly, he discusses his desire to find the stellar mass fraction in galaxies.

In this interview, Art McDonald discusses: careerlong work around tests of the Standard Model; Sudbury Neutrino Observatory (SNO) measurement of neutrino properties that fall outside the original Standard Model; childhood and family history in Canada; master’s work on positron annihilation; time at the Kellogg Laboratory at Caltech with William Fowler; early origins of and motivations behind the SNO project; postdoc at Chalk River Nuclear Laboratory using a particle accelerator to continue experimental work on fundamental symmetries; history of Chalk River; collaborations with George Ewan; collaborations with Hamish Robertson studying the measurement and production of lithium-6; work at Princeton with Will Happer using lasers to polarize nuclei; building a continuous laser beam at Chalk River; work on parity violation in nuclei; work on the Princeton cyclotron; overseeing Kevin Coulter’s thesis project, the first use of laser-induced-spin-polarization of helium; polarized Helium-3’s current uses; technical challenges of building SNO and the transition from construction to operations; SNO and the solar neutrino problem; Herb Chen’s involvement with the design of SNO; SNOLAB; decision take position at Queen’s University; early published findings from SNO; comparison of Super-Kamiokande and SNO experiments; impact of SNO results on the understanding of the Standard Model; winning the Nobel Prize for solving the solar neutrino problem, observing that solar electron neutrinos were oscillating into muon and tau neutrinos; current work with the DarkSide-20k collaboration and how that work led to an open-source ventilator project in the midst of the COVID-19 pandemic; current SNOLAB DEAP experiment using liquid argon to attempt to detect dark matter particles. Toward the end of the interview, McDonald reflects on interrelatedness across disciplines within physics, and his ongoing curiosity in searches for dark matter and neutrino-less double beta decay. 

In this interview, Fabiola Gianotti, Director-General of CERN, reflects on being the first woman in this position and the multi-layered challenges of maintaining operations at CERN during the pandemic. She recounts her upbringing in Milan and the scientific influence of her father, who was a geologist. Gianotti describes her education at the University of Milan and her formative interactions with Carlo Rubbia at CERN. She describes her work on the LEP and ADELPH collaborations and how the cancellation of the SSC affected CERN. Gianotti narrates the origins of the LHC and parallel concentration on supersymmetry and she describes the ATLAS and CMS teams and her advisory work for P5 in the United States. She discusses her election and responsibilities as Spokesperson of ATLAS and she describes the careful process of detecting and analyzing the signals that confirmed the Higgs. Gianotti describes the unique opportunity to engage a global audience given the magnitude and interest in the discovery, and she explains LHC’s planning, post-Higgs, for new physics. She describes the shutdown period that started in 2013 and the circumstances to her being named Director-General in 2013. Gianotti surveys what has, and has not, been detected at the LHC over the past decade, and how dark matter searches at CERN are complementary to those using Xenon detectors. She conveys optimism about the high luminosity upgrade at the LHC and how she frequently operates in political realms given the international nature of CERN. At the end of the interview, Gianotti observes that current projects at the CERN are reminiscent of the buildup to the LHC, and why this bodes well for the future of experimental particle physics. 

In this interview, Fred Gilman, Buhl Professor of Theoretical Physics at Carnegie Mellon University discusses his career as a theoretical physicist and hopes for the future. He discusses being a postdoc in the theoretical physics group at SLAC and his work on deep inelastic scattering. He details his involvement with the Superconducting Super Collider and the eventual decision to shut down its construction. Gilman reflects on his involvement with the Snowmass Conference as well as his work on the High-Energy Physics Advisory Panel. Lastly, Gilman speaks about his excitement for future discoveries from the Vera Rubin Observatory and his hopes for Carnegie Mellon and their involvement with physics.

Interview with Pierre Sikivie, Distinguished Professor of Physics at the University of Florida. Sikivie explains how the social isolation imposed by the pandemic has been beneficial for his research, and he recounts his childhood in Belgium and his family’s experiences during World War II. He discusses his undergraduate work and his natural inclination toward theoretical physics, and the opportunities that led to his graduate work at Yale under the mentorship of Feza Gürsey. Sikivie explains that his initial interests were in elementary particle physics which was the topic of his research on Grand Unification and the E6 group. He describes his postdoctoral research at the University of Maryland where he worked on CP violation, and he explains his decision to pursue his next postdoctoral position at SLAC to work on non-Abelian classical theories. Sikivie explains that his interests in cosmology and astrophysics only developed during his subsequent work at CERN, and the circumstances that led to axion research becoming his academic focal point. He describes his appointment to the faculty at the University of Florida and when he became sure that axions would prove to be a career-long pursuit. He narrates his invention of the axion haloscope and how this research evolved into the ADMX collaboration. Sikivie explains why he was, and remains, optimistic about the centrality of axion research to the discovery of dark matter, and he discusses the import of QCD on axion physics over the past thirty years. At the end, Sikivie surveys some of the challenges working in a field whose promise remains in some way hypothetical but which nonetheless holds promise for fundamental discovery.