Physics
Showing 201-300 of 404 Results
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Andrei Linde
Humanities and Sciences Professor
BioWhat is the origin and the global structure of the universe?
For a long time, scientists believed that our universe was born in the big bang, as an expanding ball of fire. This scenario dramatically changed during the last 35 years. Now we think that initially the universe was rapidly inflating, being in an unstable energetic vacuum-like state. It became hot only later, when this vacuum-like state decayed. Quantum fluctuations produced during inflation are responsible for galaxy formation. In some places, these quantum fluctuations are so large that they can produce new rapidly expanding parts of the universe. This process makes the universe immortal and transforms it into a multiverse, a huge fractal consisting of many exponentially large parts with different laws of low-energy physics operating in each of them.
Professor Linde is one of the authors of inflationary theory and of the theory of an eternal inflationary multiverse. His work emphasizes the cosmological implications of string theory and supergravity.
Current areas of focus:
- Construction of realistic models of inflation based on supergravity and string theory
- Investigation of conceptual issues related to the theory of inflationary multiverse -
John Lipa
Professor (Research) of Physics, Emeritus
BioJohn Lipa received his PhD at the University of Western Austrailia. He has acted as an assistant professor, senior research associate, and professor at Stanford University. Research interests include testing of various aspects of the renormalization group theory of cooperative phase transitions.
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Raghu Mahajan
Senior Research Scientist
Current Research and Scholarly InterestsMy research interests are wide-ranging:
1) In the context of gravity, how does spacetime emerge from its dual quantum system? How does the dual quantum system encode the answers to questions that involve local physics in semi-classical gravity? How do you avoid the "firewall" paradox in the context of black-hole evaporation?
2) How do you calculate electrical and heat currents in strongly-coupled many-body systems? How do you explain the linear-in-temperature resistivity in high-temperature cuprates?
3) Use tensor network methods to study electrical and heat transport and also the real-time dynamics of systems out of thermal equilibrium. -
Dimitrios (Dimitris) Ntounis
Ph.D. Student in Physics, admitted Summer 2022
Current Research and Scholarly InterestsExperimental Particle Physics, High Energy Physics, Future Colliders
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Vahe Petrosian
Professor of Physics and of Applied Physics
BioHow do things evolve in the universe? How are particles accelerated in the universe?
Professor Petrosian’s research covers many topics in the broad area of theoretical astrophysics and cosmology, with a strong focus on high-energy astrophysical processes.
Cosmological studies deal with global properties of the universe, where the main focus is the understanding of the evolution of the universe at high redshifts, through studies of the evolutions of population of sources such as galaxies and quasars or active galactic nuclei, gamma-ray bursts, using new statistical techniques developed in collaboration with Prof. B. Efron of the Department of Statistics. Another area of research is the use of gravitational lensing in measuring mass in the universe.
High-energy astrophysics research involves interpretation of non-thermal astronomical sources where particles are accelerated to very high energies and emit various kinds of radiation. These processes occur on many scales and in all sorts of objects: in the magnetosphere of planets, in the interplanetary space, during solar and stellar flares, in the accretion disks and jets around stellar-size and super-massive black holes, at centers of galaxies, in gamma-ray bursts, in supernovae, and in the intra-cluster medium of clusters of galaxies. Plasma physics processes common in all these sources for acceleration of particles and their radiative signature is the main focus of the research here. -
Xiaoliang Qi
Professor of Physics
BioMy current research interest is the interplay of quantum entanglement, quantum gravity and quantum chaos. The characterization of quantum information and quantum entanglement has provided novel understanding to space-time geometry, and relate the dynamics of chaotic many-body systems to the dynamics of space-time, i.e. quantum gravity theory. Based on recent progress in holographic duality (also known as AdS/CFT), my goal is to use tools such as tensor networks and solvable models to provide more microscopic understanding to the emergent space-time geometry from quantum states and quantum dynamics.
I am also interested in topological states and topological phenomena in condensed matter systems.
You can find my recent research topics in some talks online:
http://online.kitp.ucsb.edu/online/chord18/opgrowth/
https://www.youtube.com/watch?v=__9VBaLfC6Y&t=42s
http://online.kitp.ucsb.edu/online/qinfo_c17/qi/ -
Stephen Quake
Lee Otterson Professor in the School of Engineering and Professor of Bioengineering, of Applied Physics and, by courtesy, of Physics
Current Research and Scholarly InterestsSingle molecule biophysics, precision force measurement, micro and nano fabrication with soft materials, integrated microfluidics and large scale biological automation.
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Srinivas Raghu
Professor of Physics
BioI am interested in the emergent behavior of quantum condensed matter systems. Some recent research topics include non-Fermi liquids, quantum criticality, statistical mechanics of strongly interacting and disordered quantum systems, physics of the half-filled Landau level, quantum Hall to insulator transitions, superconductor-metal-insulator transitions, and the phenomenology of quantum materials.
Past contributions that I'm particularly proud of include the co-founding of the subject of topological photonics (with Duncan Haldane), scaling theories of non-Fermi liquid metals (with Shamit Kachru and Gonzalo Torroba), Euclidean lattice descriptions of Chern-Simons matter theories and their dualities in 2+1 dimensions (with Jing-Yuan Chen and Jun Ho Son), and 'dual' perspectives of quantum Hall transitions (with Prashant Kumar and Michael Mulligan). -
Monika Schleier-Smith
Associate Professor of Physics
Current Research and Scholarly InterestsIn between the few-particle realm where we have mastered quantum mechanics and the macroscopic domain describable by classical physics, there lies a broad swath of territory where quantum effects are relevant but still largely out of our control and partly beyond our comprehension. This territory includes metrological instruments whose precision is limited by the quantum projection noise of millions of atoms; and materials whose bulk properties emerge from many-body interactions intractable to simulation on classical computers. Professor Schleier-Smith’s research aims to advance our control and understanding of many-particle quantum systems by engineering new quantum states and Hamiltonians with ensembles of laser-cooled atoms.
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H Schwettman
Professor of Physics, Emeritus
BioAlan received his PhD from Rice University. He has acted as a research associate, associate professor, and professor at Stanford University. Research interests include the development of optical techniques that exploit the unique capabilities of the Free Electron Laser (FEL) in materials and biomedical research.
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Zhi-Xun Shen
Paul Pigott Professor of Physical Sciences, Professor of Applied Physics, of Physics and Senior Fellow at the Precourt Institute for Energy
Current Research and Scholarly InterestsDr. Shen's main research interest lies in the area of condensed matter and materials physics, as well as the applications of materials and devices. He develops photon based innovative instrumentation and advanced experimental techniques, ranging from angle-resolved photoemission to microwave imaging, soft x-ray scattering and time domain spectroscopy and scattering. He has created a body of literature that advanced our understanding of quantum materials, including superconductors, semiconductors, novel magnets, topological insulators, novel carbon and electron emitters. He is best known for his discoveries of the momentum structure of anisotropic d-wave pairing gap and anomalous normal state pseudogap in high temperature superconductors. He has further leveraged the advanced characterization tool to make better materials through thin film and interface engineering.
