3,204 research outputs found
Formation of Hot Planets by a combination of planet scattering, tidal circularization, and Kozai mechanism
We have investigated the formation of close-in extrasolar giant planets
through a coupling effect of mutual scattering, Kozai mechanism, and tidal
circularization, by orbital integrations. We have carried out orbital
integrations of three planets with Jupiter-mass, directly including the effect
of tidal circularization. We have found that in about 30% runs close-in planets
are formed, which is much higher than suggested by previous studies. We have
found that Kozai mechanism by outer planets is responsible for the formation of
close-in planets. During the three-planet orbital crossing, the Kozai
excitation is repeated and the eccentricity is often increased secularly to
values close enough to unity for tidal circularization to transform the inner
planet to a close-in planet. Since a moderate eccentricity can remain for the
close-in planet, this mechanism may account for the observed close-in planets
with moderate eccentricities and without nearby secondary planets. Since these
planets also remain a broad range of orbital inclinations (even retrograde
ones), the contribution of this process would be clarified by more observations
of Rossiter-McLaughlin effects for transiting planets.Comment: 15 pages, 16 figures, Accepted for publication in Ap
Superior Semicircular Canal Dehiscence in a Patient with Ehlers-Danlos Syndrome: A Case Report.
Superior semicircular canal dehiscence (SSCD) is a bony defect in the middle cranial fossa floor that results in an abnormal connection between the inner ear and cranial vault. Although the etiology of SSCD remains unclear, an inappropriately thin or fragile temporal bone likely predisposes an individual towards developing SSCD. Ehlers-Danlos syndrome (EDS) constitutes a group of genetic connective tissue disorders caused by a defect in the production, processing, or structure of collagen, or its associated proteins. The possible association between SSCD and EDS has not been previously described in the literature. We herein report a case of a 50-year-old female with EDS-hypermobility type who presented with a 15-year history of migraines, vertigo, and tinnitus. The patient was subsequently diagnosed with bilateral SSCD and underwent a right middle fossa (pre-auricular infratemporal) craniotomy for SSCD repair. She reported significant improvement in her auditory and vestibular symptoms, with the exception of continued mild dizziness and disequilibrium at the 3-month follow-up. Due to the rare reports of auditory symptoms in EDS, this case study highlights the importance of considering an otological consultation for auditory manifestations in a patient with EDS and illustrates a potential association between EDS and SSCD
Extended supersymmetry and its reduction on a circle with point singularities
We investigate -extended supersymmetry in one-dimensional quantum
mechanics on a circle with point singularities. For any integer ,
supercharges are explicitly constructed in terms of discrete transformations,
and a class of singularities compatible with supersymmetry is clarified. In our
formulation, the supersymmetry can be reduced to -extended supersymmetry for
any integer . The degeneracy of the spectrum and spontaneous supersymmetry
breaking are also studied.Comment: 36 pages, 5 figures, 2 table
Development of a New in vivo Double Autoradiogram for the Analysis of Dopaminergic System of the Rat Brain
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