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What will we learn from the CMB?

Description: Within the next decade, experiments measuring the anisotropies in the cosmic microwave background (CMB) will add greatly to our knowledge of the universe. There are dozens of experiments scheduled to take data over the next several years, capped by the satellite missions of NASA (MAP) and ESA (PLANCK). What will we learn from these experiments? I argue that the potential pay-off is immense: We are quite likely to determine cosmological parameters to unprecedented accuracy. This will provide key… more
Date: October 1, 1997
Creator: Dodelson, S.
Partner: UNT Libraries Government Documents Department
open access

Gravitational microlensing results from MACHO

Description: The MACHO project is searching for dark qter inthe form of massive compact haio objects (Machos), by monitoring the brightness of millions of stars in the Magellanic Clouds to search for gravitational microlensing events. Analysis of our 1st 2.3 years of data for 8.5 million stars in the LMC yields 8 candidate microlensing events, well in excess of the {approx} 1 event expected from lensing by known low-mass stars. The event timescales range from 34 to 145 days, and the estimated optical depth … more
Date: September 1, 1996
Creator: Alcock, C. & Collaboration, MACHO
Partner: UNT Libraries Government Documents Department
open access

Homoclinic orbits and chaos in a second-harmonic generating optical cavity

Description: We present two large families of Silnikov-type homoclinic orbits in a two mode-model that describes second-harmonic generation in a passive optical cavity. These families of homoclinic orbits give rise to chaotic dynamics in the model. 4 refs., 1 fig.
Date: April 1, 1997
Creator: Holm, D. & Kovacic, G., Timofeyev, I.
Partner: UNT Libraries Government Documents Department
open access

QSO Color Selection in the SDSS

Description: The Sloan Digital Sky Survey (SDSS) will image 10,000 square degrees in the north galactic cap in five filters. We hope to identify and obtain spectra for about 100,000 quasars brighter than 20th magnitude in this area. The selection will be primarily on the basis of point spread function and colors, but we will also identify quasars from a catalog of FIRST radio sources. The selection areas in color space must be determined during the testing period prior to the official start of the survey. T… more
Date: January 1, 1998
Creator: Newberg, H. J. & Yanny, B.
Partner: UNT Libraries Government Documents Department
open access

Technicolor: status and prospects

Description: Technicolor models are briefly reviewed, and a number of promising signatures at hadron colliders are described. Low-scale technicolor should be discoverable in Run 11 of the Fermilab Tevatron; failing that, it would be hard to miss at the LHC. While technicolor models may be unfashionable, it is important to search for their signatures; we do not know how nature has chosen to break electroweak symmetry.
Date: September 1, 1997
Creator: Womersley, J.
Partner: UNT Libraries Government Documents Department
open access

Dealing with quantum weirdness: Holism and related issues

Description: Various issues are discussed in interpretation of quantum mechanics. All these explorations point toward the same conclusion, that some systems are holistically connected, i.e., some composite systems have properties that cannot, even in principle, be reduced to the properties of its subsystems. This is argued to be the central metaphysical lesson of quantum theory; this will remain pertinent even if quantum mechanics gets replaced by a superior theory. Chap. 2 discusses nonlocality and rules o… more
Date: December 1, 1995
Creator: Elby, A.R.
Partner: UNT Libraries Government Documents Department
open access

Universality and clustering in 1 + 1 dimensional superstring-bit models

Description: We construct a 1+1 dimensional superstring-bit model for D=3 Type IIB superstring. This low dimension model escapes the problem encountered in higher dimension models: (1) It possesses full Galilean supersymmetry; (2) For noninteracting Polymers of bits, the exactly soluble linear superpotential describing bit interactions is in a large universality class of superpotentials which includes ones bounded at spatial infinity; (3) The latter are used to construct a superstring-bit model with the clu… more
Date: March 1, 1996
Creator: Bergman, Oren & Thorn, Charles B.
Partner: UNT Libraries Government Documents Department
open access

A Summary of the results obtained in the LDRD project "Interaction of a magnetized plasma with structured surfaces- from devices to spacecraft"

Description: Our work was directed towards developing a basic understanding of a new class of phenomena: effects of surface structure on the processes in a magnetized plasma near surfaces and at some distances for them. The surface structures can be of various kinds: topographic features ranging from smooth �waviness� to a coarse �roughness,� non-uniformities of the secondary emission coefficient, dielectric impregnations into conducting surface, etc. The expected effects are strongest when the magnetic fie… more
Date: February 23, 1999
Creator: Cohen, R. H.; Porter, G. D. & Ryutov, D. D.
Partner: UNT Libraries Government Documents Department
open access

A 2.14 ms candidate optical pulsar in SN1987A: Ten years after

Description: We have monitored Supernova 1987A in optical/near-infrared bands from a few weeks following its birth until the present time in order to search for a pulsar remnant. We have found an apparent pattern of emission near the frequency of 467.5 Hz - a 2.14 ms pulsar candidate, first detected in data taken on the remnant at the Las Campanas Observatory (LCO) 2.5-m Dupont telescope during 14-16 Feb. 1992 UT. We detected further signals near the 2.14 ms period on numerous occasions over the next four y… more
Date: September 1, 1997
Creator: Middleditch, J.; Kristian, J. A.; Kunkel, W. E.; Hill, K. M. & Watson, R. D.
Partner: UNT Libraries Government Documents Department
open access

Summary of sessions on nuclear reaction mechanisms

Description: A summary is provided to the sessions on nuclear reaction mechanisms of the International Conference on Nuclear Data for Science and Technology held May 19-24, 1997 in Trieste, Italy. Brief descriptions of Fission, Optical Model, Radiative capture of fast nucleons, codes, and new approaches are provide.
Date: May 1, 1997
Creator: Dietrich, F.S.
Partner: UNT Libraries Government Documents Department
open access

Linear dichroism and resonant photoemission in Gd 011

Description: Magnetic Linear Dichroism in Angular Distributions (MLDAD) from Photoelectron Emission was used to probe the nature of Resonant Photoemission. Gd 5p and Gd 4f emission were investigated. Using novel theoretical simulations, we were able to show that temporal matching is a requirement for ``True`` Resonant Photoemission, where the Resonant Photoemission retains the characteristics of Photoelectron Emission.
Date: May 13, 1998
Creator: Mishra, S. R.; Cummins, T. R.; Gammon, W. J.; van der Laan, G.; Goodman, K. W. & Tobin, J. G.
Partner: UNT Libraries Government Documents Department
open access

PG 0946+301: the Rosetta Stone of BALQSOs?

Description: We describe the motivation and features of a multiwavelength spectroscopic campaign on broad absorption line (BAL) QSO PG 0946+301. The main goal of this project is to determine the ionization equilibrium and abundances (IEA) in BAL outflows. Previous studies of IEA in BALQSOs were based on the assumption that the BALs are not saturated so that the column densities inferred from the apparent optical depths are realistic. This critical assumption is at odds with several recent observations and w… more
Date: June 1, 1998
Creator: Arav, N., LLNL
Partner: UNT Libraries Government Documents Department
open access

An investigation of resonant photoemission in Gd with x-ray linear dichroism

Description: The constructive summing of direct and indirect channels above the absorption threshold of a core level can cause a massive increase in the emission cross section, leading to a phenomenon called "resonant photoemission". Using novel magnetic linear dichroism in angular distribution photoelectron spectroscopy experiments and theoretical simulations, we have probed the nature of the resonant photoemission process in Gd metal. It now appears that temporal matching as well as energy matching is a r… more
Date: July 1, 1998
Creator: Tobin, J G
Partner: UNT Libraries Government Documents Department
open access

Science of consciousness and the hard problem

Description: Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to simi… more
Date: May 22, 1996
Creator: Stapp, Henry P.
Partner: UNT Libraries Government Documents Department
open access

Bayesian analysis of the solar neutrino anomaly

Description: We present an analysis of the recent solar neutrino data from the five experiments using Bayesian approach. We extract quantitative and easily understandable information pertaining to the solar neutrino problem. The probability distributions for the individual neutrino fluxes and, discrepancy distribution for B and Be fluxes, which include theoretical and experimental uncertainties have been extracted. The analysis carried out assuming that the neutrinos are unaltered during their passage from … more
Date: February 1, 1998
Creator: Bhat, C.M.
Partner: UNT Libraries Government Documents Department
open access

MACHO RR lyrae stars in the galactic bulge: the spatial distribution

Description: We have analyzed a sample of 1150 type ab, and 550 type c RR Lyrae stars found in 24 bulge fields of the MACHO database. These fields cover a range in Galactocentric distances from 0.3 to 1.6 kpc. In combination with the data on the outer bulge fields of Alard (1997) and Wesselink (1987), here we present the surface density distribution of bulge RR Lyrae between 0.3 and 3 kpc. The distribution along the line of sight of the bulge RR Lyrae population was examined on the basis of the mean magnitu… more
Date: August 1, 1997
Creator: Minniti, D.; Alcock, C. & Alves, D.
Partner: UNT Libraries Government Documents Department
open access

Error analysis for fast scintillator-based ICF burn history measurements

Description: Plastic scintillator material acts as a neutron-to-light converter in instruments that make ICF burn history measurements. Light output for a detected neutron has a fast rise time (420 ps) and a relatively long decay constant (1.2 ns). For a burst of neutrons whose duration is much shorter than the decay constant, instantaneous light output is approximately proportional to the integral of the neutron interaction rate with the scintillator material. Burn history is obtained by deconvolving the e… more
Date: July 6, 1998
Creator: Lerche, R A & Ognibene, T J
Partner: UNT Libraries Government Documents Department
open access

Matrix membranes and integrability

Description: This is a pedagogical digest of results reported in Curtright, Fairlie, {ampersand} Zachos 1997, and an explicit implementation of Euler`s construction for the solution of the Poisson Bracket dual Nahm equation. But it does not cover 9 and 10-dimensional systems, and subsequent progress on them Fairlie 1997. Cubic interactions are considered in 3 and 7 space dimensions, respectively, for bosonic membranes in Poisson Bracket form. Their symmetries and vacuum configurations are explored. Their as… more
Date: June 1, 1997
Creator: Zachos, C.; Fairlie, D. & Curtright, T.
Partner: UNT Libraries Government Documents Department
open access

Large-scale search for dark-matter axions

Description: Early results from a large-scale search for dark matter axions are presented. In this experiment, axions constituting our dark-matter halo may be resonantly converted to monochromatic microwave photons in a high-Q microwave cavity permeated by a strong magnetic field. Sensitivity at the level of one important axion model (KSVZ) has been demonstrated.
Date: January 1, 1998
Creator: Hagmann, C. A.; Kinion, D.; Stoeffl, W.; Van Bibber, K.; Daw, E. J.; McBride, J. et al.
Partner: UNT Libraries Government Documents Department
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