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California Institute of Technology Division of Physics, Mathematics and Astronomy

Works: 1,871 works in 2,092 publications in 1 language and 2,269 library holdings
Genres: Academic theses  Observations 
Classifications: QC179, 523.844
Publication Timeline
Publications about California Institute of Technology
Publications by California Institute of Technology
Most widely held works about California Institute of Technology
Most widely held works by California Institute of Technology
Bridging the gap : elusive explosions in the local universe by Mansi M Kasliwal( file )
2 editions published in 2011 in English and held by 3 libraries worldwide
"For centuries, we have known that our dynamic universe is adorned by cosmic fireworks: energetic and ephemeral beacons of light from a single star that are a million (nova) to a billion (supernova) times brighter than our sun. However, it had been an age-old conundrum that the brightest nova is approximately 1000 times fainter than the faintest supernova; why should nature leave such a wide "gap"? In search of an answer, I undertook three systematic surveys for my thesis. Since I was looking for transients fainter, faster and rarer than supernovae, I focused my search on galaxies in the local universe. We now have convincing evidence of multiple, distinct populations of rare transients bridging this "gap". Perhaps, we are witnessing new stellar physics --- shell detonations in ultra-compact white dwarf binaries, electron-capture supernovae, white dwarfs collapsing into neutron stars and birth of black-holes. A small number of intensively followed-up discoveries of elusive transients sets the stage for population studies with the upcoming "Large Synoptic Survey Telescope". This effort works towards building a complete inventory of transients in the local universe (d <200 Mpc). It better prepares us for the search for potential electromagnetic counterparts to events in the emerging fields of gravitational wave, neutrino and ultra high energy cosmic ray astronomy as these experiments are also limited to the local universe."
Ultrahigh and microwave frequency nanomechanical systems by Xue Ming Henry Huang( Book )
1 edition published in 2004 in English and held by 3 libraries worldwide
Nanodevices that operate with fundamental frequencies in the previously inaccessible microwave range (greater than 1 gigahertz) have been constructed. Two advances have been crucial to breaking the 1-GHz barrier in nanoelectromechanical systems (NEMS): the use of 3C-silicon carbide epilayers, and the development of balanced, high frequency displacement transducers. This achievement represents a significant advance in the quest for extremely high frequency nanoelectromechanical systems
Brane models and the hierarchy problem by Walter D Goldberger( Archival Material )
2 editions published in 2001 in English and held by 3 libraries worldwide
"It has been recently proposed that higher-dimensional field theory models in the presence of extended defects ("branes") may play a role in addressing the gauge hierarchy problem. In this thesis we consider several aspects of such field theories. First we perform the Kaluza-Klein reduction of a bulk scalar field propagating in the scenario of Randall and Sundrum, which consists of a region of five-dimensional anti-deSitter space bounded by two three-branes. We then propose a simple mechanism, based on the dynamics of a bulk scalar field, for stabilizing the modulus field (the "radion") corresponding to the size of the compact dimension in the Randall-Sundrum scenario. Some implications of this stabilization mechanism for low-energy phenomenology are described. Next, we investigate the one-loop quantum corrections to the radion effective potential. We show that for large brane separation, the quantum effects are power suppressed and therefore have a negligible effect on the bulk dynamics once a classical stabilization mechanism is in place. Finally, we study the ultraviolet divergence structure of field theory in the presence of branes and find that brane-localized divergences arise both at the classical and quantum level. We show how to interpret the classical divergences by the usual regularization and renormalization procedure of quantum field theory."
Controlling quantum information by Andrew J Landahl( Archival Material )
2 editions published in 2002 in English and held by 3 libraries worldwide
"Quantum information science explores ways in which quantum physical laws can be harnessed to control the acquisition, transmission, protection, and processing of information. This field has seen explosive growth in the past several years from progress on both theoretical and experimental fronts. Essential to this endeavor are methods for controlling quantum information. In this thesis, I present three new approaches for controlling quantum information. First, I present a new protocol for continuously protecting unknown quantum states from noise. This protocol combines and expands ideas from the theories of quantum error correction and quantum feedback control. The result can outperform either approach by itself. I generalize this protocol to all known quantum stabilizer codes, and study its application to the three-qubit repetition code in detail via Monte Carlo simulations. Next, I present several new protocols for controlling quantum information that are fault-tolerant. These protocols require only local quantum processing due to the topological properties of the quantum error correcting codes upon which they are built. I show that each protocol's fault-dependence behavior exhibits an order-disorder phase transition when mapped onto an associated statistical-mechanical model. I review the critical error rates of these protocols found by numerical study of the associated models, and I present new analytic bounds for them using a self-avoiding random walk argument. Moreover, I discuss fault-tolerant procedures for encoding, error-correction, computing, and decoding quantum information using these protocols, and calculate the accuracy threshold of fault-tolerant quantum memory for protocols using them. I end by presenting a new class of quantum algorithms that solve combinatorial optimization problems solely by measurement. I compute the running times of these algorithms by establishing an explicit dynamical model for the measurement process. This model, the digitized version of von Neumann's measurement model, is recognized as Kitaev's phase estimation algorithm. I show that the running times of these algorithms are closely related to the running times of adiabatic quantum algorithms. Finally, I present a two-measurement algorithm that achieves a quadratic speedup for Grover's unstructured search problem."
Diffusion in amorphous media by Mihail S Iotov( Book )
2 editions published in 1998 in English and held by 3 libraries worldwide
The energetics and environments of Swift gamma-ray bursts by Stephen Bradley Cenko( Book )
1 edition published in 2009 in English and held by 3 libraries worldwide
Magnetohydrodynamic turbulence by Jason Maron( Archival Material )
2 editions published in 2001 in English and held by 3 libraries worldwide
We simulate incompressible, MHD turbulence using a pseudo-spectral code
The radio variability of gamma-ray blazars by Joseph Lee Richards( file )
2 editions published in 2012 in English and held by 3 libraries worldwide
Experiments with a laser interferometric gravitational wave antenna by Michael Edward Zucker( Book )
3 editions published in 1989 in English and held by 3 libraries worldwide
The nodal boundary condition method : wave functions and transition probabilities for atoms with two valence electrons by T. M Helliwell( Book )
3 editions published in 1963 in English and held by 3 libraries worldwide
Discovery of non-zero neutrino mixing angle Theta13 using Daya Bay antineutrino detectors by Raymond Hei Man Tsang( file )
3 editions published in 2013 in English and held by 3 libraries worldwide
Signal extraction and optical design for an advanced gravitational wave interferometer by James E Mason( Archival Material )
2 editions published in 2001 in English and held by 3 libraries worldwide
"The LIGO project is two 4 km baseline interferometers which are currently being constructed in the quest to directly detect gravitational radiation. Concurrent with this effort is research aimed at increasing the strain sensitivity of the initial interferometers to 2.5 x 10⁻²³/[square root]Hz. The optical configuration, which defines the detector gain and bandwidth, is one such area of research. Resonant sideband extraction (RSE) is the configuration which is proposed for advanced LIGO. RSE allows for much more freedom in the optimization of the detector response compared to the initial configuration. The principle of RSE is examined in the context of a three mirror coupled cavity. The effect of optical losses on the design of an RSE interferometer is discussed. Two model optimizations of the interferometer design are done: one for binary inspiral sources and one for periodic sources at 1 kHz. An optical heterodyne signal extraction scheme is proposed to sense the deviation of the mirrors away from their nominal positions, and to read out the gravitational wave signal. The scheme is applied to the two model interferometers previously designed, and its performance is analyzed for each case. Allowable residual deviations of the common mode degrees of freedom are also derived. A tabletop prototype of an RSE interferometer has been constructed to demonstrate both the viability of the proposed signal extraction scheme and the tunability of the RSE interferometer. Good agreement on both counts is found between the measured experimental data and the modeled predictions. The coupling of laser frequency and amplitude noise into the gravitational wave readout port is analyzed for the RSE configuration assuming the proposed gravitational wave signal readout scheme. Specifications for the allowable laser frequency and amplitude noise, as well as allowable residual deviations of the differential mode degrees of freedom, are derived for the two model interferometers."
The arithmetic and geometry of a class of algebraic surfaces of general type and geometric genus one by Christopher M Lyons( Archival Material )
2 editions published in 2010 in English and held by 3 libraries worldwide
The spectra of galactic and extragalactic radio sources by Kenneth I Kellermann( Book )
1 edition published in 1963 in English and held by 3 libraries worldwide
Nuclear reactions with a proton magnetic spectrograph by Cheng Wu Li( Book )
3 editions published in 1951 in English and held by 3 libraries worldwide
Analytic functions in general analysis by Angus E Taylor( Book )
1 edition published in 1936 in English and held by 2 libraries worldwide
Experimental and analytical studies of merging plasma loops on the Caltech solar loop experiment by Rory James Perkins( Book )
2 editions published in 2011 in English and held by 2 libraries worldwide
Brown dwarf companions to young solar analogs : an adaptive optics survey using Palomar and Keck by Stanimir Metchev( Book )
1 edition published in 2006 in English and held by 2 libraries worldwide
Studies of electroweak interactions and searches for new physics using photonic events with missing energy at the Large Electron-Positron Collider by Marat I Gataullin( Book )
1 edition published in 2006 in English and held by 2 libraries worldwide
Biophysical and network mechanisms of high frequency extracellular potentials in the rat hippocampus by Erik W Schomburg( Archival Material )
2 editions published in 2014 in English and held by 2 libraries worldwide
A fundamental question in neuroscience is how distributed networks of neurons communicate and coordinate dynamically and specifically. Several models propose that oscillating local networks can transiently couple to each other through phase-locked firing. Coherent local field potentials (LFP) between synaptically connected regions is often presented as evidence for such coupling. The physiological correlates of LFP signals depend on many anatomical and physiological factors, however, and how the underlying neural processes collectively generate features of different spatiotemporal scales is poorly understood. High frequency oscillations in the hippocampus, including gamma rhythms (30-100 Hz) that are organized by the theta oscillations (5-10 Hz) during active exploration and REM sleep, as well as sharp wave-ripples (SWRs, 140-200 Hz) during immobility or slow wave sleep, have each been associated with various aspects of learning and memory. Deciphering their physiology and functional consequences is crucial to understanding the operation of the hippocampal network. We investigated the origins and coordination of high frequency LFPs in the hippocampo-entorhinal network using both biophysical models and analyses of large-scale recordings in behaving and sleeping rats. We found that the synchronization of pyramidal cell spikes substantially shapes, or even dominates, the electrical signature of SWRs in area CA1 of the hippocampus. The precise mechanisms coordinating this synchrony are still unresolved, but they appear to also affect CA1 activity during theta oscillations. The input to CA1, which often arrives in the form of gamma-frequency waves of activity from area CA3 and layer 3 of entorhinal cortex (EC3), did not strongly influence the timing of CA1 pyramidal cells. Rather, our data are more consistent with local network interactions governing pyramidal cells' spike timing during the integration of their inputs. Furthermore, the relative timing of input from EC3 and CA3 during the theta cycle matched that found in previous work to engage mechanisms for synapse modification and active dendritic processes. Our work demonstrates how local networks interact with upstream inputs to generate a coordinated hippocampal output during behavior and sleep, in the form of theta-gamma coupling and SWRs
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Alternative Names
California Institute of Technology. Division of Physics, Mathematics & Astronomy
California Institute of Technology, Pasadena. Division of Physics, Mathematics and Astronomy
California Institute of Technology. Physics, Mathematics & Astronomy
California Institute of Technology. PM&A
California Institute of Technology. PMA Division
English (45)
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