Now showing items 791-810 of 813

    • Variational and nonvariational principles in quantum transport calculations 

      Yang, Z. Q.; Tackett, A.; Di Ventra, M. (American Physical Society, 2002-07)
      A variational principle is not generally satisfied in steady-state quantum transport as opposed to the case of ground-state problems. We show that for a short-range potential, a functional for the scattering amplitude can ...
    • Variational ground state for the periodic Anderson model 

      Bowen, Samuel P.; Mancini, Jay D. (American Institute of Physics, 1988-04-15)
      A variational calculation of the ground state of the Anderson lattice model is discussed. The calculation creates a finite Hamiltonian matrix for many_electron states, which are appropriate for the thermodynamic limit. A ...
    • Variational study of the spin-gap phase of the one-dimensional t-J model 

      Chen, Y. C.; Lee, T. K. (American Physical Society, 1996-10-01)
      We propose a correlated spin-singlet-pair wave function to describe the spin-gap phase of the one-dimensional t-J model at low density and large J/t. In addition to having singlet pairs, this wave function has a Jastrow ...
    • Viability of competing field theories for the driven lattice gas 

      Schmittmann, B.; Janssen, H. K.; Täuber, Uwe C.; Zia, R. K. P.; Leung, K. T.; Cardy, J. L. (American Physical Soc, 2000-05-01)
    • Viability of competing field theories for the driven lattice gas 

      Schmittmann, B.; Janssen, H. K.; Täuber, Uwe C.; Zia, R. K. P.; Leung, K. T.; Cardy, J. L. (American Physical Society, 2000-05)
      It has recently been suggested that the driven lattice gas should be described by an alternate held theory in the limit of infinite drive. We review the original and the alternate field theory, invoking several well-documented ...
    • Vlasov theory of plasma oscillations: linear-approximation 

      Arthur, M. D.; Greenberg, W.; Zweifel, P. F. (AIP Publishing, 1977)
      A functional analytic approach to the linearized collisionless Vlasov equation is presented utilizing a resolvent integration technique on the resolvent of the transport operator evaluated at a particular point. Formulae ...
    • Volume holograms constructed from computer-generated masks 

      Case, S. K.; Dallas, W. J. (Optical Society of America, 1978-05)
      A new type of hologram that combines computer-generated holograms with volume holograms is described. This hologram allows arbitrary selection of the location and color of a computer-generated image when white light ...
    • Vortex transport and voltage noise in disordered superconductors 

      Das, Jayajit; Bullard, Thomas J.; Täuber, Uwe C. (Elsevier Science Bv, 2003-02-01)
      We study, by means of three-dimensional Monte Carlo simulations, the current–voltage (I–V) characteristics and the voltage noise spectrum at low temperatures of driven magnetic flux lines interacting with randomly placed ...
    • Vortex washboard voltage noise in type-II superconductors 

      Bullard, T. J.; Das, J.; Daquila, G. L.; Täuber, Uwe C. (Springer, 2008-10-01)
    • The W mass and the U parameter 

      Takeuchi, T.; Loinaz, W.; Okamura, N.; Wijewardhana, L. C. R. (2003)
    • Water-pollution monitoring using matched spatial filters 

      Almeida, S. P.; Eu, J. K. T. (Optical Society of America, 1976-02)
      Presented are some results obtained from the application of matched spatial filtering techniques to the identification of biological specimens called diatoms (i.e., water algae). A prototype semiautomatic optical processor ...
    • Weak hard X-ray emission from two broad absorption line quasars observed with NuSTAR: Compton-thick absorption or intrinsic X-ray weakness? 

      Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fabian, A. C.; Farrah, D.; Fiore, F.; Fuerst, F.; Grefenstette, B. W.; Hailey, C. J.; Hickox, R.; Madsen, K. K.; Matt, G.; Ogle, P.; Risaliti, G.; Saez, C.; Teng, S. H.; Walton, D. J.; Zhang, W. W. (IOP Publishing Ltd., 2013-08)
      We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray ...
    • Weakly pinned Bose glass vs Mott insulator phase in superconductors 

      Wengel, C.; Täuber, Uwe C. (1997-06-23)
    • Why double-stranded RNA resists condensation 

      Tolokh, Igor S.; Pabit, Suzette A.; Katz, Andrea M.; Chen, Yujie; Drozdetski, Aleksander; Baker, Nathan; Pollack, Lois; Onufriev, Alexey V. (2014-09-15)
      The addition of small amounts of multivalent cations to solutions containing double-stranded DNA leads to inter-DNA attraction and eventual condensation. Surprisingly, the condensation is suppressed in double-stranded RNA, ...
    • Wilson lines and Chern-Simons flux in explicit heterotic Calabi-Yau compactifications 

      Apruzzi, Fabio; Gautason, Fridrik Freyr; Parameswaran, Susha; Zagermann, Marco (Springer, 2015-02-27)
      We study to what extent Wilson lines in heterotic Calabi-Yau compactifications lead to non-trivial H-flux via Chern-Simons terms. Wilson lines are basic ingredients for Standard Model constructions but their induced H-flux ...
    • WISE detections of known QSOs at redshifts greater than six 

      Blain, A. W.; Assef, R.; Stern, D.; Tsai, C. W.; Eisenhardt, P.; Bridge, C.; Benford, D.; Jarrett, T.; Cutri, R.; Petty, S.; Wu, J. W.; Wright, E. L. (IOP Publishing Ltd., 2013-12)
      We present WISE All-Sky mid-infrared (IR) survey detections of 55% (17/31) of the known QSOs at z > 6 from a range of surveys: the SDSS, the CFHT-LS, FIRST, Spitzer, and UKIDSS. The WISE catalog thus provides a substantial ...
    • Witten index for noncompact dynamics 

      Lee, Seung-Joo; Yi, Piljin (Springer, 2016-06-16)
      Among gauged dynamics motivated by string theory, we find many with gapless asymptotic directions. Although the natural boundary condition for ground states is L-2, one often turns on chemical potentials or supersymmetric ...
    • Wulff shapes and the critical nucleus for a triangular Ising lattice 

      Shneidman, V. A.; Zia, R. K. P. (American Physical Society, 2001-02)
      Equilibrium Wulff shapes and interfacial energies of two-dimensional "crystals" on a triangular lattice are considered. Asymptotic approximations are constructed for both the shapes and energies in the limit T-->0 where ...
    • X-ray absorption analysis of MCG-6-30-15: Discerning three kinematic systems 

      Holczer, T.; Behar, E.; Arav, Nahum (IOP Publishing Ltd., 2010-01)
      By analyzing the X-ray spectrum of MCG -6-30-15 obtained with the High Energy Transmission Grating (HETGS) spectrometer on board the Chandra observatory, we identify three kinematically distinct absorption systems; two ...