physics & astronomy

The Universe as a Detector: What can we learn about fundamental physics from Cosmology?



Dr. Harsh Mathur Case Western Reserve University The imprint of primordial gravitational radiation on the cosmic microwave background polarization, if observed, is considered smoking gun proof of inflation. I will discuss how such an observation can not only provide information about the Universe in the epoch of inflation but also constrain theories of grand unification. In the second part of the talk I will discuss tests of gravity on scales ranging from the tabletop to the cosmological scale. Such tests may shed light on physics beyond the standard model.



Defects with Character: Majorana Local Modes in Condensed-Matter Systems



Dr. Bertrand Halperin Harvard University Theory predicts the existence of some peculiar phases of quantum condensed matter systems that have multiple degrees of freedom with very low energy, when localized “defects” are introduced. I shall focus on a class of these phases where each defect has half of a conventional degree of freedom, and the defects may be considered as sites for localized zero-energy states of a “Majorana fermion”. Such defects would also exhibit the intriguing property of “non-Abelian statistics” -- i.e., if various defects can be moved around each other, or if two identical defects can be interchanged, the result is a unitary transformation on the quantum mechanical state that depends on the order in which operations are performed but is insensitive to many other details. In my talk, I will try to explain these various concepts and discuss the attempts to realize them in condensed matter systems.



Rapid Arctic warming and extreme weather events in mid-latitudes: Are they connected?



Dr. Jennifer Francis Rutgers University In this presentation, I will discuss the hypothesis proposed by Francis and Vavrus (2012) that links rapid Arctic warming (so-called Arctic amplification) to changes in the large-scale atmospheric circulation in the northern hemisphere that favors more persistent weather patterns and a higher likelihood of extreme weather events such as droughts, cold spells, flooding, heavy snows, and heat waves. This hypothesis has been a topic of considerable controversy in recent months, particularly regarding its relationship to the unusual weather conditions that persisted in the winter of 2013/2014. I will discuss various aspects of this linkage, what we know and don't know, and present new related research.



Science Policy in America



Dr. Tyler Glembo The American Physical Society Science Policy in America Fundamental scientific research, as a majority federally funded initiative, is becoming more deeply embedded in politics. Since the end of the Space Race, funding of basic physical sciences research as a percent GDP has continuously declined, indicating that policy makers see funding scientific research as less of a priority than they once did. Indeed, a lack of understanding about both science and how science is done amongst members of Congress has led to both reduced prioritization and also to misguided attempts at regulation, such as making peer review a public process and considering Congressional oversight for specific grants. Here we will examine a few current issues in science policy and the need for physicists to effectively weigh in on such policy issues. We will also consider the positive or negative effects such public engagement may have on our scientific careers and ways in which you can get involved.



A&S Hall of Fame 2014 - Dr. Keith B. MacAdam

Keith B. MacAdam was born in Rochester, N.Y., attended Swarthmore College and earned a doctorate in Physics in 1971. After research at University of Stirling in Scotland, Yale University, and the University of Arizona, he came to UK as an Assistant Professor in 1977. He built a campus-based research program in experimental atomic-molecular-optical (AMO) physics with students and post-docs, supported by the National Science Foundation and the Research Corporation. He was appointed Professor of Physics in 1986 and was a University Research Professor in 1990-91.

MacAdam’s research in crossed-beam collisions between charged particles and laser-excited atoms in highly excited “Rydberg” states was widely recognized in the international AMO physics community. He was elected a Fellow of the American Physical Society in 1987. Research in Aarhus, Denmark, Boulder, Colo., and Stockholm, Sweden, extended his international connections.

At UK MacAdam was active in all aspects of teaching, research and service. He taught with success at levels from first-year to graduate, and he introduced and continues to teach a non-majors’ physics course “How Things Work.” He served as Chair of the Department of Physics & Astronomy (1997-2001), on the College Executive Committee (Chair, 2007-08) and on many campus-wide committees. MacAdam was honored by the naming of the UK MacAdam Student Observatory, which opened in 2008 to serve the campus and community.



A&S Celebrates New Hall of Fame Members

The University of Kentucky College of Arts Sciences Hall of Fame induction and festivities are slated for Friday, Oct. 10, at 3:30 p.m. in the Recital Hall of the UK Singletary Center for the Arts.

Unravelling the Mysteries of Neutrinos

Dr. Stephen Parke Fermilab Neutrinos are the most numerous massive particles in the Universe. Their masses are very tiny, no larger than one millionth the mass of the electron. Are they like all the known massive fermions, being four component particles, or are they a new type of fermion never seen before, a two component fermion? Are there only only three neutrinos or are there more species of neutrinos? Of the three neutrinos we know of, we have determined part of the massing pattern but not the completely pattern. Also we have measured some of their mixing parameters with reasonable precision via neutrino oscillation experiments but not all. Do neutrinos violate CP in neutrino oscillations? Can neutrinos help explain the baryon-antibaryon asymmetry of the Universe? I will address many of the important questions about the neutrinos and how the future Fermilab program will address some of these questions.



Ultra High Energy Cosmic Rays: Recent results from the Pierre Auger Observatory



Dr. Fred Sarazin Colorado School of Mines The cosmic ray spectrum spans many orders of magnitude in energy. At the very end of the spectrum (E>10^18 eV) lie the Ultra High Energy cosmic rays (UHECRs). Their origin remains largely unknown and their study is made difficult in part by the very low flux impinging on Earth's atmosphere. The Pierre Auger Observatory, located in the Mendoza province of Argentina, is an array of detectors spread over 3000 km^2 specifically designed to study the properties of the extensive air showers induced by the UHECRs in the atmosphere. The Observatory is fully operational since 2008 and is operated by a collaboration of more than 500 scientists and engineers from 19 countries. In this colloquium, a selection of recent results obtained by the Observatory and the plan for the upcoming upgrade will be presented.



On The Road Again

Top Eigenvalue of a Random Matrix: A tale of tails

Dr. Satya Majumdar 

CNRS Paris

The statistical properties of the largest eigenvalue of a random matrix are of interest in diverse fields such as in the stability of large ecosystems, in disordered systems, in statistical data analysis and even in string theory. In this talk I'll discuss some recent developments in the theory of extremely rare fluctuations (large deviations) of the largest eigenvalue using a Coulomb gas method. Such rare fluctuations have also been measured in recent experiments in coupled laser systems. I'll also discuss recent applications of this Coulomb gas method in three different problems: entanglement in a bipartite system, conductance fluctuation through a mesoscopic cavity and the vicious random walkers problem. 



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