140,461 research outputs found
Green's function for the Relativistic Coulomb System via Sum Over Perturbation Series
We evaluate the Green's function of the D-dimensional relativistic Coulomb
system via sum over perturbation series which is obtained by expanding the
exponential containing the potential term in the path integral
into a power series. The energy spectra and wave functions are extracted from
the resulting amplitude.Comment: 13 pages, ReVTeX, no figure
Internal Gravity Waves Modulate the Apparent Misalignment of Exoplanets around Hot Stars
We propose that the observed misalignment between extra-solar planets and
their hot host stars can be explained by angular momentum transport within the
host star. Observations have shown that this misalignment is preferentially
around hot stars, which have convective cores and extended radiative envelopes.
This situation is amenable to substantial angular momentum transport by
internal gravity waves (IGW) generated at the convective-radiative interface.
Here we present numerical simulations of this process and show that IGW can
modulate the surface rotation of the star. With these two- dimensional
simulations we show that IGW could explain the retrograde orbits observed in
systems such as HAT-P-6 and HAT-P-7, however, extension to high obliquity
objects will await future three- dimensional simulations. We note that these
results also imply that individual massive stars should show temporal
variations in their v sini measurements.Comment: 6 pages, 2 figures, Accepted for publication in ApJ
Path integral for a relativistic Aharonov-Bohm-Coulomb system
The path integral for the relativistic spinless Aharonov-Bohm-Coulomb system
is solved, and the energy spectra are extracted from the resulting amplitude.Comment: 6 pages, Revte
Origin of the pseudogap and its influence on superconducting state
When holes move in the background of strong antiferromagnetic correlation,
two effects with different spatial scale emerge, leading to a much reduced
hopping integral with an additional phase factor. An effective Hamiltonian is
then proposed to investigate the underdoped cuprates. We argue that the
pseudogap is the consequence of dressed hole moving in the antiferromagnetic
background and has nothing to do with the superconductivity. The momentum
distributions of the gap are qualitatively consistent with the recent ARPES
measurements both in the pseudogap and superconducting state. Two thermal
qualities are further calculated to justify our model. A two-gap scenario is
concluded to describe the relation between the two gaps.Comment: 7 pages, 5 figure
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