50,062 research outputs found
Abelian Dominance in Wilson Loops
It has been conjectured that the Abelian projection of QCD is responsible for
the confinement of color. Using a gauge independent definition of the Abelian
projection which does {\it not} employ any gauge fixing, we provide a strong
evidence for the Abelian dominance in Wilson loop integral. In specific we
prove that the gauge potential which contributes to the Wilson loop integral is
precisely the one restricted by the Abelian projection.Comment: 4 pages, no figure, revtex. Phys. Rev. D in pres
Color Reflection Invariance and Monopole Condensation in QCD
We review the quantum instability of the Savvidy-Nielsen-Olesen (SNO) vacuum
of the one-loop effective action of SU(2) QCD, and point out a critical defect
in the calculation of the functional determinant of the gluon loop in the SNO
effective action. We prove that the gauge invariance, in particular the color
reflection invariance, exclude the unstable tachyonic modes from the gluon loop
integral. This guarantees the stability of the magnetic condensation in QCD.Comment: 28 pages, 3 figures, JHEP styl
On Signatures of Atmospheric Features in Thermal Phase Curves of Hot Jupiters
Turbulence is ubiquitous in Solar System planetary atmospheres. In hot
Jupiter atmospheres, the combination of moderately slow rotation and thick
pressure scale height may result in dynamical weather structures with unusually
large, planetary-size scales. Using equivalent-barotropic, turbulent
circulation models, we illustrate how such structures can generate a variety of
features in the thermal phase curves of hot Jupiters, including phase shifts
and deviations from periodicity. Such features may have been spotted in the
recent infrared phase curve of HD 189733b. Despite inherent difficulties with
the interpretation of disk-integrated quantities, phase curves promise to offer
unique constraints on the nature of the circulation regime present on hot
Jupiters.Comment: 22 pages, 6 figures, 1 table, accepted for publication in Ap
Stability of the Magnetic Monopole Condensate in three- and four-colour QCD
It is argued that the ground state of three- and four-colour QCD contains a
monopole condensate, necessary for the dual Meissner effect to be the mechanism
of confinement, and support its stability on the grounds that it gives the
off-diagonal gluons an effective mass sufficient to remove the unstable ground
state mode.Comment: jhep.cls, typos corrected, references added, some content delete
A strongly inhomogeneous superfluid in an iron-based superconductor
Among the mysteries surrounding unconventional, strongly correlated
superconductors is the possibility of spatial variations in their superfluid
density. We use atomic-resolution Josephson scanning tunneling microscopy to
reveal a strongly inhomogeneous superfluid in the iron-based superconductor
FeTe0.55Se0.45. By simultaneously measuring the topographic and electronic
properties, we find that this inhomogeneity in the superfluid density is not
caused by structural disorder or strong inter-pocket scattering, and does not
correlate with variations in Cooper pair-breaking gap. Instead, we see a clear
spatial correlation between superfluid density and quasiparticle strength,
putting the iron-based superconductors on equal footing with the cuprates and
demonstrating that locally, the quasiparticles are sharpest when the
superconductivity is strongest. When repeated at different temperatures, our
technique could further help elucidate what local and global mechanisms limit
the critical temperature in unconventional superconductors
Scaling laws for light weight optics, studies of light weight mirrors mounting and dynamic mirror stress, and light weight mirror and mount designs
Scaling laws for light-weight optical systems are examined. A cubic relationship between mirror diameter and weight has been suggested and used by many designers of optical systems as the best description for all light-weight mirrors. A survey of existing light-weight systems in the open literature was made to clarify this issue. Fifty existing optical systems were surveyed with all varieties of light-weight mirrors including glass and beryllium structured mirrors, contoured mirrors, and very thin solid mirrors. These mirrors were then categorized and weight to diameter ratio was plotted to find a best curve for each case. A best fitting curve program tests nineteen different equations and ranks a goodness-to-fit for each of these equations. The resulting relationship found for each light-weight mirror category helps to quantify light-weight optical systems and methods of fabrication and provides comparisons between mirror types
Changing Face of the Extrasolar Giant Planet, HD 209458b
High-resolution atmospheric flow simulations of the tidally-locked extrasolar
giant planet, HD 209458b, show large-scale spatio-temporal variability. This is
in contrast to the simple, permanent day/night (i.e., hot/cold) picture. The
planet's global circulation is characterized by a polar vortex in motion around
each pole and a banded structure corresponding to ~3 broad zonal (east-west)
jets. For very strong jets, the circulation-induced temperature difference
between moving hot and cold regions can reach up to ~1000 K, suggesting that
atmospheric variability could be observed in the planet's spectral and
photometric signatures.Comment: 6 pages, 1 ps figure, 2 low-res color figures (JPEG). Figure 3
updated. Contact authors for hi-res versions of color figures. Accepted for
publication in ApJ
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