Excess profits taxes of commercial banks

Bank profits ; Banks and banking - Accounting

Black hole hunting in the Andromeda Galaxy

We present a new technique for identifying stellar mass black holes in low mass X-ray binaries (LMXBs), and apply it to XMM-Newton observations of M31. We examine X-ray time series variability seeking power density spectra (PDS) typical of LMXBs accreting at a low accretion rate (which we refer to as Type A PDS); these are very similar for black hole and neutron star LMXBs. Galactic neutron star LMXBs exhibit Type A PDS at low luminosities (~10^36--10^37 erg/s) while black hole LMXBs can exhibit them at luminosities >10^38 erg/s. We propose that Type A PDS are confined to luminosities below a critical fraction of the Eddington limit, $l_c$ that is constant for all LMXBs; we have examined asample of black hole and neutron star LMXBs and find they are all consistent with $l_c$ = 0.10+/-0.04 in the 0.3--10 keV band. We present luminosity and PDS data from 167 observations of X-ray binaries in M31 that provide strong support for our hypothesis. Since the theoretical maximum mass for a neutron star is \~3.1 M_Sun, we therefore assert that any LMXB that exhibits a Type A PDS at a 0.3--10 keV luminosity greater than 4 x 10^37 erg/s is likely to contain a black hole primary. We have found eleven new black hole candidates in M31 using this method. We focus on XMM-Newton observations of RX J0042.4+4112, an X-ray source in M31 and find the mass of the primary to be 7+/-2 M_Sun, if our assumptions are correct. Furthermore, RX J0042.4+4112 is consistently bright in \~40 observations made over 23 years, and is likely to be a persistently bright LMXB; by contrast all known Galactic black hole LMXBs are transient. Hence our method may be used to find black holes in known, persistently bright Galactic LMXBs and also in LMXBs in other galaxies.Comment: 6 Pages, 6 figures. To appear in the conference proceedings of "Interacting Binaries: Accretion, Evolution and Outcomes" (Cefalu, July 4-10 2004

Search for Cosmic Axions using an Optical Interferometer

A high finesse optical cavity can be used to search for cosmic axions in the mass range 10^{-6}< m_a <10^{-4} eV. Either a two-arm or a single-arm cavity is suitable and in either case the signal as resonant sidebands imposed on the carrier. Assuming for the local axion density the usual figure of 500 MeV/cm^3 [8], the KSVZ axion line [4] g/m_a = 0.4 Gev^{-2}, can be reached over the full mass range in a one year search.Comment: 4 pages, 2 figur

Dark matter axions

The hypothesis of an `invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order $10^{-5}$ eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.Comment: 12 pages, invited talk at the Workshop `Crossing the Boundaries: Gauge Dynamics at Strong Coupling' in honor of Misha Shifman's 60th birthday, March 14-17, 2009, in Minneapolis, M

Rage Against the Machines: How Subjects Learn to Play Against Computers

We use an experiment to explore how subjects learn to play against computers which are programmed to follow one of a number of standard learning algorithms. The learning theories are (unbeknown to subjects) a best response process, fictitious play, imitation, reinforcement learning, and a trial & error process. We test whether subjects try to influence those algorithms to their advantage in a forward-looking way (strategic teaching). We find that strategic teaching occurs frequently and that all learning algorithms are subject to exploitation with the notable exception of imitation. The experiment was conducted, both, on the internet and in the usual laboratory setting. We find some systematic differences, which however can be traced to the different incentives structures rather than the experimental environment.learning, fictitious play, imitation, reinforcement, trial & error, strategic teaching, Cournot duopoly, experiments, internet

The Higgs portal and an unified model for dark energy and dark matter

We examine a scenario where the Higgs boson is coupled to an additional singlet scalar field which we identify with a quintessence field. We show that this results in an unified picture of dark matter and dark energy, where dark energy is the zero-mode classical field rolling the usual quintessence potential and the dark matter candidate is the quantum excitation (particle) of the field, which is produced in the universe due to its coupling to the Higgs boson.Comment: 5 pages, no figures. New references and acknowledgment adde

Strategic Analysis of the U.S. Quarter Horse Industry, Emphasizing California

The American Quarter Horse is the most popular breed of horse in California, as well as nationwide. This breed has shaped agricultural history and has had a major impact on the agricultural economy because. The objective of this report is to provide strategic information about the U.S. quarter horse industry, with an emphasis on California. This report provides information on the following topics: statistics of the industry, quarter horse associations, trends in the industry, prevailing marketing practices, innovative/successful marketing practices, success factors for horse businesses, and characterization of related and supporting industries. The primary contribution of the report is a diagram and description of the horse industry supply chain. The varying levels of entry barriers and varying degrees of attractiveness to potential entrants are given for many types of businesses in the horse industry.American Quarter Horse, associations, breeder, California, entry barriers, equine, horse industry, industry trends, livestock, marketing practices, registry, related and supporting industries, supply chain, success factors, trainer, Agribusiness, Livestock Production/Industries,

Rage Against the Machines: How Subjects Learn to Play Against Computers

We use an experiment to explore how subjects learn to play against computers which are programmed to follow one of a number of standard learning algorithms. The learning theories are (unbeknown to subjects) a best response process, fictitious play, imitation, reinforcement learning, and a trial & error process. We test whether subjects try to influence those algorithms to their advantage in a forward-looking way (strategic teaching). We find that strategic teaching occurs frequently and that all learning algorithms are subject to exploitation with the notable exception of imitation. The experiment was conducted, both, on the internet and in the usual laboratory setting. We find some systematic differences, which however can be traced to the different incentives structures rather than the experimental environment

Relationship Between the Azimuthal Dependencies of Nuclear Modification Factor and Ridge Yield

The azimuthal angular dependence of the nuclear modification factor R_{AA}(p_T, phi,N_{part}) recently obtained by PHENIX is related at low p_T to the trigger phi dependence of the ridge yield as measured by STAR in a framework in which the azimuthal anisotropy is driven by semihard scattering near the surface. Careful consideration of the initial geometry leads to the determination of a surface segment in which the production of semihard partons are responsible for the phi dependence of the inclusive distribution on the one hand, and for the angular correlation in ridge phenomenology on the other. With v_2 also being well reproduced along with R_{AA} and ridge yield, all relevant phi dependencies in heavy-ion collisions can now be understood in a unified description that emphasizes the ridge production whether or not a trigger is used.Comment: This expanded version has additional discussions that render the paper more readable without change of substance. It is to be published in Phys. Rev.