Functional determinants on certain domains

Functional determinants on various domains of the sphere and flat space are presented for scalar and spinor fields.Comment: 14p, plain TeX, talk presented at the 6th Moscow Quantum Gravity Seminar, Moscow, June 12-19, 1995.(Minor errors corrected.

The C_2 heat-kernel coefficient in the presence of boundary discontinuities

We consider the heat-kernel on a manifold whose boundary is piecewise smooth. The set of independent geometrical quantities required to construct an expression for the contribution of the boundary discontinuities to the C_{2} heat-kernel coefficient is derived in the case of a scalar field with Dirichlet and Robin boundary conditions. The coefficient is then determined using conformal symmetry and evaluation on some specific manifolds. For the Robin case a perturbation technique is also developed and employed. The contributions to the smeared heat-kernel coefficient and cocycle function are calculated. Some incomplete results for spinor fields with mixed conditions are also presented.Comment: 25 pages, LaTe

Planetary Companions Around Two Solar Type Stars: HD 195019 and HD 217107

We have enlarged the sample of stars in the planet search at Lick Observatory. Doppler measurements of 82 new stars observed at Lick Observatory, with additional velocities from Keck Observatory, have revealed two new planet candidates. The G3V/IV star, HD 195019, exhibits Keplerian velocity variations with a period of 18.27 d, an orbital eccentricity of 0.03 +/- 0.03, and M sin i = 3.51 M_Jup. Based on a measurement of Ca II H&K emission, this star is chromospherically inactive. We estimate the metallicity of HD 195019 to be approximately solar from ubvy photometry. The second planet candidate was detected around HD 217107, a G7V star. This star exhibits a 7.12 d Keplerian period with eccentricity 0.14 +/- 0.05 and M sin i = 1.27 M_Jup. HD 217107 is also chromospherically inactive. The photometric metallicity is found to be [Fe/H] = +0.29 +/- 0.1 dex. Given the relatively short orbital period, the absence of tidal spin-up of HD 217107 provides a theoretical constraint on the upper limit of the companion mass of < 11 M_Jup.Comment: 15 pages, plus 6 figures. To appear in Jan 1999 PAS

A comparison of a structured home-based rehabilitation programme with conventional supervised pulmonary rehabilitation:A randomised non-inferiority trial

Background: Standardised home-based pulmonary rehabilitation (PR) programmes offer an alternative model to centre-based supervised PR for which uptake is currently poor. We determined if a structured home-based unsupervised PR programme was non-inferior to supervised centre-based PR for participants with COPD. Methods: A total of 287 participants with COPD who were referred to PR (187 male, mean (SD) age 68 (8.86) years, FEV1% predicted 48.34 (17.92)) were recruited. They were randomised to either centre-based PR or a structured unsupervised home-based PR programme including a hospital visit with a healthcare professional trained in motivational interviewing, a self-management manual and two telephone calls. Fifty-eight (20%) withdrew from the centre-based group and 51 (18%) from the home group. The primary outcome was dyspnoea domain in the chronic respiratory disease questionnaire (Chronic Respiratory Questionnaire Self-Report; CRQ-SR) at 7 weeks. Measures were taken blinded. We undertook a modified intention-to-treat (mITT) complete case analysis, comparing groups according to original random allocation and with complete data at follow-up. The non-inferiority margin was 0.5 units. Results: There was evidence of significant gains in CRQ-dyspnoea at 7 weeks in both home and centre-based groups. There was inconclusive evidence that home-based PR was non-inferior to PR in dyspnoea (mean group difference, mITT: −0.24, 95% CI −0.61 to 0.12, p=0.18), favouring the centre group at 7 weeks. Conclusions: The standardised home-based programme provides benefits in dyspnoea. Further evidence is needed to definitively determine if the health benefits of the standardised home-based programme are non-inferior or equivalent to supervised centre-based rehabilitation

Ten Low Mass Companions from the Keck Precision Velocity Survey

Ten new low mass companions have emerged from the Keck precision Doppler velocity survey, with minimum (msini) masses ranging from 0.8 mjup to 0.34 msun. Five of these are planet candidates with msini < 12 mjup, two are brown dwarf candidates with msini ~30 mjup, and three are low mass stellar companions. Hipparcos astrometry reveals the orbital inclinations and masses for three of the (more massive) companions, and it provides upper limits to the masses for the rest. A new class of extrasolar planet is emerging, characterized by nearly circular orbits and orbital radii greater than 1 AU. The planet HD 4208b appears to be a member of this new class. The mass distribution of extrasolar planets continues to exhibit a rapid rise from 10 mjup toward the lowest detectable masses near 1 msat.Comment: 26 pages, TeX, plus 13 postscript figure

Hyperspherical entanglement entropy

The coefficient of the log term in the entanglement entropy associated with hyperspherical surfaces in flat space-time is shown to equal the conformal anomaly by conformally transforming Euclideanised space--time to a sphere and using already existing formulae for the relevant heat--kernel coefficients after cyclic factoring. The analytical reason for the result is that the conformal anomaly on the lune has an extremum at the ordinary sphere limit. A proof is given. Agreement with a recent evaluation of the coefficient is found.Comment: 7 pages. Final revision. Historical comments amended. Minor remarks adde

Characterization the Cool KOIs. II. The M Dwarf KOI-254 and its Hot Jupiter

We report the confirmation and characterization of a transiting gas giant planet orbiting the M dwarf KOI-254 every 2.455239 days, which was originally discovered by the Kepler mission. We use radial velocity measurements, adaptive optics imaging, and near-infrared spectroscopy to confirm the planetary nature of the transit events. KOI-254 b is the first hot Jupiter discovered around an M-type dwarf star. We also present a new model-independent method of using broadband photometry to estimate the mass and metallicity of an M dwarf without relying on a direct distance measurement. Included in this methodology is a new photometric metallicity calibration based on J – K colors. We use this technique to measure the physical properties of KOI-254 and its planet. We measure a planet mass of M_P = 0.505 M_(Jup), radius R_P = 0.96 R_(Jup), and semimajor axis a = 0.030 AU, based on our measured stellar mass M_* = 0.59 M_☉ and radius R_* = 0.55 R_☉. We also find that the host star is metal-rich, which is consistent with the sample of M-type stars known to harbor giant planets