1,276,284 research outputs found
New transformation of Wigner operator in phase space quantum mechanics for the two-mode entangled case
As a natural extension of Fan's paper (arXiv: 0903.1769vl [quant-ph]) by
employing the formula of operators' Weyl ordering expansion and the bipartite
entangled state representation we find new two-fold complex integration
transformation about the Wigner operator (in its entangled form) in phase space
quantum mechanics and its inverse transformation. In this way, some operator
ordering problems can be solved and the contents of phase space quantum
mechanics can be enriched.Comment: 8 pages, 0 figure
From the Complete Yang Model to Snyder's Model, de Sitter Special Relativity and Their Duality
By means of Dirac procedure, we re-examine Yang's quantized space-time model,
its relation to Snyder's model, the de Sitter special relativity and their
UV-IR duality. Starting from a dimensionless dS_5-space in a 5+1-d Mink-space a
complete Yang model at both classical and quantum level can be presented and
there really exist Snyder's model, the dS special relativity and the duality.Comment: 7 papge
Wigner functions of thermo number state, photon subtracted and added thermo vacuum state at finite temperature
Based on Takahashi-Umezawa thermo field dynamics and the order-invariance of
Weyl ordered operators under similar transformations, we present a new approach
to deriving the exact Wigner functions of thermo number state, photon
subtracted and added thermo vacuum state. We find that these Wigner functions
are related to the Gaussian-Laguerre type functions of temperature, whose
statistical properties are then analysed.Comment: 10 pages and 2 figure
Ab initio approach to s-shell hypernuclei 3H_Lambda, 4H_Lambda, 4He_Lambda and 5He_Lambda with a Lambda N-Sigma N interaction
Variational calculations for s-shell hypernuclei are performed by explicitly
including degrees of freedom. Four sets of YN interactions (SC97d(S),
SC97e(S), SC97f(S) and SC89(S)) are used. The bound-state solution of
He is obtained and a large energy expectation value of the tensor
transition part is found. The internal energy of the
He subsystem is strongly affected by the presence of a particle
with the strong tensor transition potential.Comment: Phys. Rev. Lett. 89, 142504 (2002
Chiral Symmetry and Electron-Electron Interaction in Many-Body Gap Formation in Graphene
We study a many-body ground state of graphene in perpendicular magnetic
fields. Chiral symmetry in graphene enables us to determine the many-body
ground state, which turns out to be a doubly degenerate chiral condensate for
the half-filled (undoped) case. In the ground state a prominent charge
accumulation emerges along zigzag edges. We also show that gapless excitations
are absent despite the presence of the robust edge modes, which is consistent
with the Chern number C = 0.Comment: 4 pages, 3 figures, proceeding of 26th International Conference on
Low Temperature Physics (LT26
Environmental Dependence of Cold Dark Matter Halo Formation
We use a high-resolution -body simulation to study how the formation of
cold dark matter (CDM) halos is affected by their environments, and how such
environmental effects produce the age-dependence of halo clustering observed in
recent -body simulations. We estimate, for each halo selected at redshift
, an `initial' mass defined to be the mass enclosed by the
largest sphere which contains the initial barycenter of the halo particles and
within which the mean linear density is equal to the critical value for
spherical collapse at . For halos of a given final mass, , the
ratio has large scatter, and the scatter is larger for
halos of lower final masses. Halos that form earlier on average have larger
, and so correspond to higher peaks in the initial density
field than their final masses imply. Old halos are more strongly clustered than
younger ones of the same mass because their initial masses are larger. The
age-dependence of clustering for low-mass halos is entirely due to the
difference in the initial/final mass ratio. Low-mass old halos are almost
always located in the vicinity of big structures, and their old ages are
largely due to the fact that their mass accretions are suppressed by the hot
environments produced by the tidal fields of the larger structure. The
age-dependence of clustering is weaker for more massive halos because the
heating by large-scale tidal fields is less important.Comment: 18 pages,19 figures, accepted by MNRA
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