325 research outputs found
Monte Carlo Simulation Calculation of Critical Coupling Constant for Continuum \phi^4_2
We perform a Monte Carlo simulation calculation of the critical coupling
constant for the continuum {\lambda \over 4} \phi^4_2 theory. The critical
coupling constant we obtain is [{\lambda \over \mu^2}]_crit=10.24(3).Comment: 11 pages, 4 figures, LaTe
Pharmacological therapies for fibromyalgia (fibromyalgia syndrome) in adults – an overview of Cochrane Reviews (Protocol).
This is a protocol for a Cochrane Review (overview). The objectives are as follows:To provide an overview of the therapeutic efficacy of pharmacological therapies for fibromyalgia (fibromyalgia syndrome) in adults, and to report on adverse events associated with their use. The major comparison of interest will be with placebo
Reply
No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78300/1/20291_ftp.pd
Ultrafast optically induced spin transfer in ferromagnetic alloys
The vision of using light to manipulate electronic and spin excitations in materials on their fundamental time and length scales requires new approaches in experiment and theory to observe and understand these excitations. The ultimate speed limit for all-optical manipulation requires control schemes for which the electronic or magnetic subsystems of the materials are coherently manipulated on the time scale of the laser excitation pulse. In our work, we provide experimental evidence of such a direct, ultrafast, and coherent spin transfer between two magnetic subsystems of an alloy of Fe and Ni. Our experimental findings are fully supported by time-dependent density functional theory simulations and, hence, suggest the possibility of coherently controlling spin dynamics on subfemtosecond time scales, i.e., the birth of the research area of attomagnetism
Ultrafast optically induced spin transfer in ferromagnetic alloys
The vision of using light to manipulate electronic and spin excitations in materials on their fundamental time and length scales requires new approaches in experiment and theory to observe and understand these excitations. The ultimate speed limit for all-optical manipulation requires control schemes for which the electronic or magnetic subsystems of the materials are coherently manipulated on the time scale of the laser excitation pulse. In our work, we provide experimental evidence of such a direct, ultrafast, and coherent spin transfer between two magnetic subsystems of an alloy of Fe and Ni. Our experimental findings are fully supported by time-dependent density functional theory simulations and, hence, suggest the possibility of coherently controlling spin dynamics on subfemtosecond time scales, i.e., the birth of the research area of attomagnetism
Nonequilibrium Quantum-Field Dynamics and Off-Shell Transport for -theory in 2+1 dimensions
We solve the Kadanoff-Baym equations for nonequilibrium initial
configurations of the -theory in 2+1 dimensions and compare to explicit
solutions of generalized transport equations for the same theory. The latter
transport equations are derived from the Kadanoff-Baym equation in a first
order gradient expansion in phase space and explicitly retain the off-shell
dynamics as inherent in the time-dependent spectral functions. The solutions of
these equations compare very well with the exact solutions of the full
Kadanoff-Baym equations with respect to the occupation numbers of the
individual modes, the spectral evolution as well as the chemical equilibration
process. Furthermore, the proper equilibrium off-shell distribution is reached
for large times contrary to the quasiparticle Boltzmann limit. We additionally
present a direct comparison of the solution of the generalized transport
equations in the Kadanoff-Baym and Botermans-Malfliet form; both solutions are
found to agree very well with each other.Comment: 43 pages, LaTex, including 15 postscript figures, submitted to Nucl.
Phys.
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