5,166 research outputs found
Relativistic corrections to the long range interaction between closed shell atoms
The complete correction to the long range interaction between
neutral closed shell atoms is obtained, the relation to the asymptotic
expansion of the known short range interaction at the atomic scale is presented
and a general interaction potential which is valid in the whole range of the
inter atomic distances is constructed.Comment: 9 pages, accepted for Phys. Rev.
Two-loop RGE of a general renormalizable Yang-Mills theory in a renormalization scheme with an explicit UV cutoff
We perform a systematic one-loop renormalization of a general renormalizable
Yang-Mills theory coupled to scalars and fermions using a regularization scheme
with a smooth momentum cutoff (implemented through an exponential
damping factor). We construct the necessary finite counterterms restoring the
BRST invariance of the effective action by analyzing the relevant
Slavnov-Taylor identities. We find the relation between the renormalized
parameters in our scheme and in the conventional scheme
which allow us to obtain the explicit two-loop renormalization group equations
in our scheme from the known two-loop ones in the scheme.
We calculate in our scheme the divergences of two-loop vacuum graphs in the
presence of a constant scalar background field which allow us to rederive the
two-loop beta functions for parameters of the scalar potential. We also prove
that consistent application of the proposed regularization leads to
counterterms which, together with the original action, combine to a bare action
expressed in terms of bare parameters. This, together with treating
as an intrinsic scale of a hypothetical underlying finite theory of all
interactions, offers a possibility of an unconventional solution to the
hierarchy problem if no intermediate scales between the electroweak scale and
the Planck scale exist.Comment: updated references, 90 pages, many figure
Magnetization reversal in spin patterns with complex geometry
We study field-driven dynamics of spins with antiferromagnetic interaction
along the links of a complex substrate geometry, which is modeled by graphs of
a controlled connectivity distribution. The magnetization reversal occurs in
avalanches of spin flips, which are pinned by the topological constraints of
the underlying graph. The hysteresis loop and avalanche sizes are analyzed and
classified in terms of graph's connectivity and clustering. The results are
relevant for magnets with a hierarchical spatial inhomogeneity and for design
of nanoscale magnetic devices.Comment: 4 pages, 3 color figures, revtex
Torsion in one-term distributive homology
The one-term distributive homology was introduced by J.H.Przytycki as an
atomic replacement of rack and quandle homology, which was first introduced and
developed by R.Fenn, C.Rourke and B.Sanderson, and J.S.Carter, S.Kamada and
M.Saito. This homology was initially suspected to be torsion-free, but we show
in this paper that the one-term homology of a finite spindle can have torsion.
We carefully analyze spindles of block decomposition of type (n,1) and
introduce various techniques to compute their homology precisely. In addition,
we show that any finite group can appear as the torsion subgroup of the first
homology of some finite spindle. Finally, we show that if a shelf satisfies a
certain, rather general, condition then the one-term homology is trivial.Comment: 17 pages, 2 PS-Tricks figure
Improvement of speech recognition by nonlinear noise reduction
The success of nonlinear noise reduction applied to a single channel
recording of human voice is measured in terms of the recognition rate of a
commercial speech recognition program in comparison to the optimal linear
filter. The overall performance of the nonlinear method is shown to be
superior. We hence demonstrate that an algorithm which has its roots in the
theory of nonlinear deterministic dynamics possesses a large potential in a
realistic application.Comment: see urbanowicz.org.p
Helium energy levels including corrections
The correction to energy is expressed in terms of an effective
Hamiltonian for an arbitrary state of helium. Numerical calculations
are performed for levels, and the previous result for the centroid
is corrected. While the resulting theoretical predictions for the ionization
energy are in moderate agreement with experimental values for , ,
and states, they are in significant disagreement for the singlet state
.Comment: 11 pages, with erratum submitted to Phys. Rev. A (2007
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