In Situ Formation and Dynamical Evolution of Hot Jupiter Systems

Hot Jupiters, giant extrasolar planets with orbital periods shorter than ~10 days, have long been thought to form at large radial distances, only to subsequently experience long-range inward migration. Here, we propose that in contrast with this picture, a substantial fraction of the hot Jupiter population formed in situ via the core accretion process. We show that under conditions appropriate to the inner regions of protoplanetary disks, rapid gas accretion can be initiated by Super-Earth type planets, comprising 10-20 Earth masses of refractory composition material. An in situ formation scenario leads to testable consequences, including the expectation that hot Jupiters should frequently be accompanied by additional low-mass planets with periods shorter than ~100 days. Our calculations further demonstrate that dynamical interactions during the early stages of planetary systems' lifetimes should increase the inclinations of such companions, rendering transits rare. High-precision radial velocity monitoring provides the best prospect for their detection.Comment: 19 pages, 10 figures, accepted to Ap

Pairing in High Temperature Superconductors and Berry Phase

The topological approach to the understanding of pairing mechanism in high $T_c$ superconductors analyses the relevance of the Berry phase factor in this context. This also gives the evidence for the pairing mechanism to be of magnetic origin.Comment: 6 page

Rebuilding the Foundation: Reestablishing Ethics in the Accounting Professsion

Today’s business world has become increasingly diverse in its view of ethics. This lack of objective decision-making has been made clear through the scandals and questionable accounting methods in recent years. In light of these instances, the accounting profession has taken steps to regain and ensure the public’s trust, which the profession relies on. In the absence of ethical practices, the profession loses its trustworthiness and reliability. This paper will discuss the key role of ethics in accounting and the efforts that have been made in the past and are being made currently to ensure that this vital component is preserved in the future

The Energetic Costs of Cellular Computation

Cells often perform computations in response to environmental cues. A simple example is the classic problem, first considered by Berg and Purcell, of determining the concentration of a chemical ligand in the surrounding media. On general theoretical grounds (Landuer's Principle), it is expected that such computations require cells to consume energy. Here, we explicitly calculate the energetic costs of computing ligand concentration for a simple two-component cellular network that implements a noisy version of the Berg-Purcell strategy. We show that learning about external concentrations necessitates the breaking of detailed balance and consumption of energy, with greater learning requiring more energy. Our calculations suggest that the energetic costs of cellular computation may be an important constraint on networks designed to function in resource poor environments such as the spore germination networks of bacteria.Comment: 9 Pages (including Appendix); 4 Figures; v3 corrects even more typo

Evidence for composite nature of quasiparticles in the 2D t-J model

It is shown that the dynamics of a single hole in a quantum antiferromagnet (described by the t--J model) can be simply understood in terms of a composite quasiparticle. This description provides naturally two different energy scales t and J corresponding to the inverse masses of the charge (holon) and spin (spinon) elementary excitations respectively. This picture is consistent with the exact results obtained on small clusters for the single hole spectral function and optical conductivity providing that one assumes the existence of a string-like force of magnitude J between the holon and the spinon. Then the hole quasiparticle can be interpreted as a bound state of its two constituents.Comment: 5 pages (revtex), 6 figures uuencoded, (Submitted to Nuclear Physics B

Kinetic Approach to Fractional Exclusion Statistics

We show that the kinetic approach to statistical mechanics permits an elegant and efficient treatment of fractional exclusion statistics. By using the exclusion-inclusion principle recently proposed [Phys. Rev. E49, 5103 (1994)] as a generalization of the Pauli exclusion principle, which is based on a proper definition of the transition probability between two states, we derive a variety of different statistical distributions interpolating between bosons and fermions. The Haldane exclusion principle and the Haldane-Wu fractional exclusion statistics are obtained in a natural way as particular cases. The thermodynamic properties of the statistical systems obeying the generalized exclusion-inclusion principle are discussed.Comment: 6 pages, REVTE