The equity premium puzzle and decreasing relative risk aversion

Agents are assumed to have a power risk aversion utility function in an otherwise standard asset pricing model. These preferences are shown to be capable of eliminating one version of the equity premium and risk free rate puzzles when they display decreasing relative risk aversion.asset pricing,equity premium,risk aversion

The Roche problem: some analytics

Some exact analytical formulas are derived for the potential and mass ratio as a function of Lagrangian points position, in the classical Roche model of the close binary stars.Comment: aastex, 4 pp. ApJ accepte

Solving the kilo-second QPO problem of the intermediate polar GK Persei

We detect the likely optical counterpart to previously reported X-ray QPOs in spectrophotometry of the intermediate polar GK Persei during the 1996 dwarf nova outburst. The characteristic timescales range between 4000--6000 s. Although the QPOs are an order of magnitude longer than those detected in the other dwarf novae we show that a new QPO model is not required to explain the long timescale observed. We demonstrate that the observations are consistent with oscillations being the result of normal-timescale QPOs beating with the spin period of the white dwarf. We determine the spectral class of the companion to be consistent with its quiescent classification and find no significant evidence for irradiation over its inner face. We detect the white dwarf spin period in line fluxes, V/R ratios and Doppler-broadened emission profiles.Comment: 14 pages, 11 figures. Accepted for publication in MNRA

Phase space polarization and the topological string: a case study

We review and elaborate on our discussion in hep-th/0606112 on the interplay between the target space and the worldsheet description of the open topological string partition function, for the example of the conifold. We discuss the appropriate phase space and canonical form for the system. We find a map between choices of polarization and the worldsheet description, based on which we study the behavior of the partition function under canonical transformations.Comment: 18 pages, invited review for MPL

The Be/X-ray Transient V0332+53: Evidence for a tilt between the orbit and the equatorial plane?

We present optical and infrared observations of BQ Cam, the optical counterpart to the Be/X-ray transient system V0332+53. BQ Cam is shown to be an O8-9Ve star, which places V0332+53 at a distance of ~7 kpc. H-alpha spectroscopy and infrared photometry are used to discuss the evolution of the circumstellar envelope. Due to the low inclination of the system, parameters are strongly constrained. We find strong evidence for a tilt of the orbital plane with respect to the circumstellar disc (pressumably on the equatorial plane). Even though the periastron distance is only ~ 10 R_*, during the present quiescent state the circumstellar disc does not extend to the distance of periastron passage. Under these conditions, X-ray emission is effectively prevented by centrifugal inhibition of accretion. The circumstellar disc is shown to be optically dense at optical and infrared wavelengths, which together with its small size, is taken as an indication of tidal truncation.Comment: 9 pages, 3 figures, uses mn.sty and epsfig Accepted for publication in MNRA

Assessing the clinical value of fast onset and sustained duration of action of long-acting bronchodilators for COPD

Date of Aceptance: 12/02/2015 Acknowledgments The authors were assisted in the preparation of the manuscript by Sarah Filcek, a professional medical writer at CircleScience (Tytherington, UK), part of KnowledgePoint360, an Ashfield Company. This assistance was funded by Novartis Pharmaceuticals. Copyright © 2015. Published by Elsevier Ltd.Peer reviewedPublisher PD

Persistent currents in carbon nanotubes

Persistent currents driven by a static magnetic flux parallel to the carbon nanotube axis are investigated. Owing to the hexagonal symmetry of graphene the Fermi contour expected for a 2D-lattice reduces to two points. However the electron or hole doping shifts the Fermi energy upwards or downwards and as a result, the shape of the Fermi surface changes. Such a hole doping leading to the Fermi level shift of (more or less) 1eV has been recently observed experimentally. In this paper we show that the shift of the Fermi energy changes dramatically the persistent currents and discuss the electronic structure and possible currents for zigzag as well as armchair nanotubes.Comment: 8 text pages, 6 figures, to appear in Physics Letters