68,387 research outputs found
Waveform simulator Patent
Sign wave generation simulator for variable amplitude, frequency, damping, and phase pulses for oscilloscope displa
nPI Resummation in 3D SU(N) Higgs Theory
We test the utility of the nPI formalism for solving nonperturbative dynamics
of gauge theories by applying it to study the phase diagram of SU(N) Higgs
theory in 3 Euclidean spacetime dimensions. Solutions reveal standard
signatures of a first order phase transition with a critical endpoint leading
to a crossover regime, in qualitative agreement with lattice studies. The
location of the critical endpoint, x sim 0.14 for SU(2) with a fundamental
Higgs, is in rough but not tight quantitative agreement with the lattice. We
end by commenting on the overall effectiveness and limitations of an nPI
effective action based study. In particular, we have been unable to find an nPI
gauge-fixing procedure which can simultaneously display the right phase
structure and correctly handle the large-VEV Higgs region. We explain why doing
so appears to be a serious challenge.Comment: 24 pages plus appendices, 8 figure
Waterfowl Harvest and Hunter Use at Carlyle Lake During the 1973 Season
Division of Wildlife Resources Migratory Bird Section, Periodic Report No. 7Report issued on: April 15, 197
Performance of transonic fan stage with weight flow per unit annulus area of 178 kilograms per second per square meter (6.5(lb/sec)/(sq ft))
The overall and blade-element performances are presented over the stable flow operating range from 50 to 100 percent of design speed. Stage peak efficiency of 0.834 was obtained at a weight flow of 26.4 kg/sec (58.3 lb/sec) and a pressure ratio of 1.581. The stall margin for the stage was 7.5 percent based on weight flow and pressure ratio at stall and peak efficiency conditions. The rotor minimum losses were approximately equal to design except in the blade vibration damper region. Stator minimum losses were less than design except in the tip and damper regions
Transport properties of the one-dimensional Hubbard model at finite temperature
We study finite-temperature transport properties of the one-dimensional
Hubbard model using the density matrix renormalization group. Our aim is
two-fold: First, we compute both the charge and the spin current correlation
function of the integrable model at half filling. The former decays rapidly,
implying that the corresponding Drude weight is either zero or very small.
Second, we calculate the optical charge conductivity sigma(omega) in presence
of small integrability-breaking next-nearest neighbor interactions (the
extended Hubbard model). The DC conductivity is finite and diverges as the
temperature is decreased below the gap. Our results thus suggest that the
half-filled, gapped Hubbard model is a normal charge conductor at finite
temperatures. As a testbed for our numerics, we compute sigma(omega) for the
integrable XXZ spin chain in its gapped phase
Performance of transonic fan stage with weight flow per unit annulus area of 208 kilograms per second per square meter (42.6 (lb/sec)/sq ft)
Performance was obtained for a 50-cm-diameter compressor designed for a high weight flow per unit annulus area of 208 (kg/sec)/sq m. Peak efficiency values of 0.83 and 0.79 were obtained for the rotor and stage, respectively. The stall margin for the stage was 23 percent, based on equivalent weight flow and total-pressure ratio at peak efficiency and stall
Electroweak Baryogenesis with dimension-6 Higgs interactions
We present the computation of the baryon asymmetry in the SM amplified by
dimension-6 Higgs interactions using the WKB approximation. Analyzing the
one-loop potential it turns out that the phase transition is strongly first
order in a wide range of the parameters. It is ensured not to wash out the net
baryon number gained previously even for Higgs masses up to at least 170 GeV.
In addition dimension-6 operators induce new sources of CP violation. Novel
source terms which enhance the generated baryon asymmetry emerge in the
transport equations. This model predicts a baryon to entropy ratio close to the
observed value for a large part of the parameter space.Comment: 10 pages, 4 figures, Talk given at the 8th International Moscow
School of Physic
Localization of Two-Dimensional Quantum Walks
The Grover walk, which is related to the Grover's search algorithm on a
quantum computer, is one of the typical discrete time quantum walks. However, a
localization of the two-dimensional Grover walk starting from a fixed point is
striking different from other types of quantum walks. The present paper
explains the reason why the walker who moves according to the degree-four
Grover's operator can remain at the starting point with a high probability. It
is shown that the key factor for the localization is due to the degeneration of
eigenvalues of the time evolution operator. In fact, the global time evolution
of the quantum walk on a large lattice is mainly determined by the degree of
degeneration. The dependence of the localization on the initial state is also
considered by calculating the wave function analytically.Comment: 21 pages RevTeX, 4 figures ep
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