Research
- Astrophysics & Cosmology read more ...
The astrophysics group in the Department of Physics and Astronomy at Penn currently consists of seven full time faculty, one lecturer, and a number of post-doctoral fellows, full-time staff, and graduate students. We are in the process of hiring more faculty and plan to continue expanding our group over the next several years. The astro group at Penn has a very strong experimental and theoretical interests in cosmology. We are specially strong in cosmology, galaxy evolution and stellar populations. There is a vibrant collaboration with the string cosmology group at Penn. We also do research on numerical astrophysics. Our areas of research include Kuiper-Belt objects, dark matter search, dark matter halos, large scale structure, galaxy formation and evolution, the cosmic microwave background, and the development of new astronomical instrumentation and telescopes. Our research activities cover the full spectrum -- computations, instrumentation, observation, and theory. There are many exciting projects for students to join.
- Biophysics read more ...
There is a cultural gap between physics, which seeks to understand extremely simple systems, and biology, which is obliged to study the overall behavior of extremely complex systems. One area where simplicity and life intersect is the study of biomembranes, both in isolation and as active elements of cells. In recent years amazing new experimental techniques, including optical tweezers, have opened up the study of both the equilibrium conformations and dynamic response of membranes to quantitative analysis. Similarly the DNA molecule, while architecturally complex, has remarkably simple elastic behavior governed by just a few parameters. Apart from their potential relevance to biology, the study of these systems has revealed new physical phenomena characteristic of the highly-fluctuating micron world. At UPenn we currently have groups developing the theory of lipid bilayers, the physics of single DNA molecules, as well as the structure of condensed DNA in vitro and in vivo.
- Condensed Matter read more ...
Condensed Matter physicists study matter in its nearly unlimited variety of condensed states from liquids to crystalline solids, from thin films to fabricated nanostructures, from quantum Hall electron gases to superconductors, from carbon nanotubules to liquid crystals, and from amorphous structures to complex fluids. We seek both to clarify the fundamental issues behind the striking properties of these systems, and to illuminate their potential for useful application. Condensed matter physics underlies many key devices of information technology, including the transistor, the solid-state laser, optical fiber, magnetic storage media, and the liquid crystal display.Much of the explosive growth in Condensed Matter Physics in the last decade has come at the mutual boundaries of physics, chemistry, and materials science. Recently in ever more dramatic ways, this intellectual cross-fertilization is producing key discoveries at the convergence of these fields and biology. The Penn Condensed Matter Physics group helped to create this fruitful trend, and many of our projects are highly interdisciplinary in nature.
Penn has a long and successful history of forefront research in condensed matter physics with seminal contributions to superconductivity, conducting polymers, liquid crystals, colloidal physics, and many other fields. There are currently 7 experimentalists and 7 theorists pursuing research in many areas of condensed matter physics.
- High Energy read more ...
The goal of particle physics is to understand what are the most fundamental constituents of matter and how these elementary particles interact. The next few years hold great promise for major advances in our understanding of this field of physics, both in theory and in experiment. Several new experimental facilities have just begun operation or will begin operation soon. These facilities will address fundamental questions such as
- What is the origin of electroweak symmetry breaking and mass (the Higgs sector)?
- Are there additional fundamental particles (e.g. supersymmetric partners of the known particles)?
- What is the origin of the matter anti-matter asymmetry in the Universe?
The answers to these questions not only affect the understanding of elementary particle physics; they can also have important implications for cosmology and the large-scale structure of the Universe. Theoretical particle physics is focused on understanding whether there is a unified theory that explains all elementary particles and their interactions, including gravity. The most promising approaches such as string theory and membrane theory also involve modern mathematics. One of the biggest challenges is to extract unique predictions from these theories that can be verified by experiment.
The Penn high energy physics group is active in both experiment and theory. Experimentalists in the Penn faculty are working on experiments at three new accelerators:
- The Tevatron collider with the new Main Injector at Fermilab. The
Tevatron collides protons on their antimatter counterparts,
antiprotons, at a center of mass energy of 1.96 TeV. With an almost
decade-long run from 2001 to 2009, the Tevatron is producing the
highest energy collisions of fundamental particles, at least
until the LHC begins. - The Large Hadron Collider (LHC) at CERN. This facility will be begin
operation in 2008 and will produce proton-proton collisions at almost an
order of magnitude higher energy than the Tevatron. This will be the
premier facility of the era and will address the origin of electroweak
symmetry breaking and other outstanding fundamental issues in particle
physics.
Penn has a very active and strong elementary particle physics theory group. Although many areas are pursued, the central thread is the unification of all interactions. This includes theoretical efforts in string and membrane theory, phenomenological studies of the electroweak interaction, and attempts to connect the fundamental theory with experiment. There is also considerable activity in particle astrophysics, including inflationary cosmology, studies of the microwave anisotropies, and theoretical studies of solar and supernova neutrinos.