## Physics Department

### The Raub Fund

** Established in 1996 to honor the life, career and memory of Dr. Harry L. Raub III, the Harry Raub Physics Department Endowment Fund provides annual income to support summer internship and research experiences for current physics students. Raub, professor emeritus of physics and native of Lancaster, Pa., earned his undergraduate degree at Franklin & Marshall and his Ph.D. from Cornell. Raub taught here at the College from 1947 to 1984, receiving the Christian and Mary Lindback Foundation Award for Distinguished Teaching in 1963. At the time of his death on October 2, 2004, he remained one of only two professors who took part in Muhlenberg's 100th anniversary graduation march in 1948.**

The Raub Fund at Work - Benefitting Students, Faculty and the College

**Nathan Crossette '13, Raub Fund Scholar under the direction of Dr. Adam Clark **

Nate will begin his study of string theory in the summer of 2012, supported by the Raub Fund. Under the guidance of physics professor Adam Clark, Nate will explore the correspondence between quantum field theories in our universe and string theories in non-physical universes with 6 extra dimensions and special curvature properties known as “anti-de Sitter.”

Juan Maldacena first conjectured this correspondence in 1997, and that conjecture triggered an explosion of research in the 12 years since then. Quantum field theories are the mathematical framework of the Standard Model, which is currently the best description of the fundamental particles and forces. Even so, many interesting calculations are difficult or even impossible in this framework. Researchers have amassed much evidence supporting the correspondence and exploring the properties required of both the string theories used and their equivalent quantum field theories. Unfortunately, the quantum field theories used in the correspondence so far have many properties not shared by the Standard Model. If a spacetime could be found that gives a theory equivalent to one of the forces of the Standard Model, then the difficult calculations from the Standard Model could be more easily performed using the equivalent description as a string theory.

One of the non-physical features shared by almost all of the theories that work in the correspondence is called supersymmetry. In 2003, a class of spacetimes knows as “Janus solutions” was discovered that breaks supersymmetry while preserving many of the key features that allow calculations to still be performed. Additionally, it is worth noting that the “standard” theories used in the correspondence do not contain matter in the quantum field theories. A method exists for adding matter particles analogous to the quarks that compose protons and neutrons in the Standard Model; however, as of yet this method has not been applied to theories in the “Janus solution” category. This summer, Nate will begin learning about string theory and the correspondence. By the end of the summer he will be writing computer programs to compute the mass of quarks in “Janus solution” theories.

**Tyler Huffman, Raub Fund Scholar under the direction of Dr. Adam Clark **

Mathematical models are important elements of the theories physicists develop to describe nature. Some examples are Newton’s Laws of motion and wave equations describing the behavior of electromagnetic radiation. The development of string theory started in the 1960’s as a way to describe hadrons, the family of particles including the more familiar protons and neutrons. As string theory has matured it has come to be viewed as the likely mathematical structure for a theory of everything (TOE). A TOE strives to describe all known fundamental forces with a single consistent mathematical framework.

Tyler Huffman started his study of string theory in the summer of 2009, supported by the Raub Fund. Under the guidance of physics professor Adam Clark, Tyler explored the correspondence between quantum field theories in our universe and string theories in non-physical universes with 6 extra dimensions and special curvature properties known as “anti-de Sitter.” Juan Maldacena first conjectured this correspondence in 1997, and that conjecture triggered an explosion of research in the 12 years since then. Quantum field theories are the mathematical framework of the Standard Model, which is currently the best description of the fundamental particles and forces. Even so, many interesting calculations are difficult or even impossible in this framework. Researchers have amassed much evidence supporting the correspondence and exploring the properties required of both the string theories used and their equivalent quantum field theories. Unfortunately, the quantum field theories used in the correspondence so far have many properties not shared by the Standard Model. If a spacetime could be found that gives a theory equivalent to one of the forces of the Standard Model, then the difficult calculations from the Standard Model could be more easily performed using the equivalent description as a string theory.

The correspondence remains unproven, despite the fact that it has survived every test so far where quantities can be computed in both the string theory and the quantum field theory. Recent research has discovered that quantum field theories that violate the symmetries of relativity in a particular way do not develop internal inconsistencies. If a string theory could be found that was equivalent to a quantum field theory with these violations of relativity, it would show that the correspondence is so robust that it can survive without such a stalwart pillar of modern physics as relativity. This would lend tremendous new support to the validity of the correspondence. This summer, Tyler Huffman began learning about string theory and the correspondence. By the end of the summer, Tyler began calculations of the string theory states that his advisor, Adam Clark, believes will be the string theory reflection of violations of relativity in a quantum field theory. This fall Tyler will complete those calculations. Additionally, we are now confident that these string theory states will correspond to some type of relativity violation, even if it is not the same as originally discovered in the quantum field theory. So no matter what we find, it will definitely be interesting.