Speaker Series WN2022

JAn. 20th, Prof. Kevin Kubarych

Ultrafast Optics and Spectroscopy

Title: Optical Call-and-Response: How Ultrafast Frequency Correlations Reveal Hidden Chemical Dynamics

Abstract: The fundamental motion of atoms and molecules occurs on time scales of femtoseconds and picoseconds, so direct experimental access to molecular dynamical processes requires ultrafast laser spectroscopy methods. Just over 20 years ago, when I started graduate school, a new approach to ultrafast nonlinear optical spectroscopy began to emerge based on measuring the full multiple time or frequency domain response function, rather than just projections as had been standard for decades. In this talk I will motivate the need for these advanced methods, explain some technical aspects of their implementation, and also highlight a few signature applications.

Feb. 16th, Prof. Joel Fajans

Title: The Physics of Bicycles

Abstract: The D-term is an interesting property of matter that has received a comparatively small amount of research dedicated to it compared to other global properties such as mass and spin. We discuss its potential connection to pressure and shear force distributions inside the nucleon and provide a possible means of extracting this form factor both theoretically and experimentally. We also provide a model calculation of both the A-term and D-term in ϕ3 theory, which required the modification of the energy-momentum tensor from its canonical definition to a renormalized "Improved" energy-momentum tensor.

Mar. 17th, Prof. Leopoldo Pando Zayas

Theoretical Quantum Mechanics and Gravity

Title: Quantum Black Holes in Holography

Abstract: The anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence states that for a certain quantum system with gravity there is an equivalent field theory system without gravity. I will review some recent developments within the AdS/CFT correspondence where the Bekenstein-Hawking entropy of certain black holes has been given a microscopic, statistical mechanical foundation in terms of partition functions of the dual field theories. At the quantum level, the entropy of black holes is not exactly equal to one quarter of the area of the event horizon; it receives tiny quantum corrections proportional to the logarithm of the area. I will describe how these logarithmic corrections to the black hole entropy can be computed and how to match them successfully to a microscopic description based on the AdS/CFT correspondence.

Mar. 31st, Prof. Ramón Torres-Isea

Experimental Physics

Title: A Glimpse into Professional Experimental Physics: Methods and Tools of Problem Solving

Abstract: This was a two-part presentation:

(1) An introduction to the planning, assessment, and preparation for certification of experiments; and

(2) Application of the strategies discussed in part 1 to my own research experience (a) in industry and (b) in academia: on the characterization of deuterated scintillators for fast neutron detection.

I hope to also incorporate in Part 2 highlights of results from a couple of decades of research by our group at TWINSOL -a joint UM-UND collaboration (lead at UM Physics by Prof. Emeritus Frederick D. Becchetti.)