Empirical Modelling of Contagion: A Review of Methodologies

The existing literature promotes a number of alternative methods to test for the presence of contagion during financial market crises. This paper reviews those methods, and shows how they are related in a unified framework. A number of extensions are also suggested which allow for multivarite testing, endogeneity issues and structural breaks.Contagion, Financial Crises

Planets Transiting Non-Eclipsing Binaries

The majority of binary stars do not eclipse. Current searches for transiting circumbinary planets concentrate on eclipsing binaries, and are therefore restricted to a small fraction of potential hosts. We investigate the concept of finding planets transiting non-eclipsing binaries, whose geometry would require mutually inclined planes. Using an N-body code we explore how the number and sequence of transits vary as functions of observing time and orbital parameters. The concept is then generalised thanks to a suite of simulated circumbinary systems. Binaries are constructed from RV surveys of the solar neighbourhood. They are then populated with orbiting gas giants, drawn from a range of distributions. The binary population is shown to be compatible with the Kepler eclipsing binary catalogue, indicating that the properties of binaries may be as universal as the initial mass function. These synthetic systems produce transiting circumbinary planets occurring on both eclipsing and non-eclipsing binaries. Simulated planets transiting eclipsing binaries are compared with published Kepler detections. We obtain 1) that planets transiting non-eclipsing binaries probably exist in the Kepler data, 2) that observational biases alone cannot account for the observed over-density of circumbinary planets near the stability limit, implying a physical pile-up, and 3) that the distributions of gas giants orbiting single and binary stars are likely different. Estimating the frequency of circumbinary planets is degenerate with the spread in mutual inclination. Only a minimum occurrence rate can be produced, which we find to be compatible with 9%. Searching for inclined circumbinary planets may significantly increase the population of known objects and will test our conclusions. Their existence, or absence, will reveal the true occurrence rate and help develop circumbinary planet formation theories.Comment: 19 pages, 14 figures, accepted August 2014 to A&A, minor changes to previous arXiv versio

Influence of the atomic-scale inhomogeneity of the pair interaction on extracted from the STM spectra characteristics of high-TcT_c superconductors

The influence of the atomic-scale inhomogeneities of the pairing interaction strength on the superconducting order parameter and the conductance spectra measurable by STM is studied in the framework of weak-coupling BCS-like theory for two-dimensional lattice model. First of all, it is found that the inhomogeneity having the form of atomic-scale regions of enhanced pair interaction increases the ratio of the local low-temperature gap in differential conductance spectra to the local temperature of vanishing the gap $2\Delta_g/T_p$. Even in the framework of mean-field treatment this ratio is shown to be larger than the one corresponding to the homogeneous case. It is shown that the effect of thermal phase fluctuations of the superconducting order parameter can further increase this ratio. Taking them into account in the framework of a toy model we obtained the ratio $2\Delta_g/T_p$ to be $\sim 7-8$. It is found that the additional atomic-scale hopping element disorder and weak potential scatterers, which can also take place in cuprate materials, have no considerable effect on the statistical properties of the system, including the distribution of the gaps, $T_p$ and the ratio $2\Delta_g/T_p$. The second consequence of the atomic-scale order parameter inhomogeneity is the anticorrelation between the low-temperature gap and the high-temperature zero-bias conductance. The obtained results could bear a relation to recent STM measurements.Comment: 14 pages, 13 figure

Texas Natural Resources Inventory and Monitoring System (TNRIMS). Applications Verification and ~ transfer (ASVT), Remote Sensing Information Sub system (RSIS): Unival software user's guide

There are not author-identified significant results in this report

Information from leading neutrons at HERA

In principle, leading neutrons produced in photoproduction and deep-inelastic scattering at HERA have the potential to determine the pion structure function, the neutron absorptive cross section and the form of the pion flux. To explore this potential we compare theoretical predictions for the x_L and p_t spectra of leading neutrons, and the Q^2 dependence of the cross section, with the existing ZEUS data.Comment: 17 pages, 8 figure

Checking formalism for central exclusive production in the first LHC runs

We discuss how the early LHC data runs can provide crucial tests of the formalism used to predict the cross sections of central exclusive production.Comment: 7 pages, 6 figures; Based on a talk by A.D. Martin at the CERN - DESY Workshop "HERA and the LHC", 26 - 30 May 2008, CER

Electromagnetic properties of baryons

We discuss the chiral behavior of nucleon and Delta(1232) electromagnetic properties within the framework of a SU(2) covariant baryon chiral perturbation theory. Our one-loop calculation is complete to the order p^3 and p^4/Delta with Delta as the Delta(1232)-nucleon energy gap. We show that the magnetic moment of a resonance can be defined through the linear energy shift only when an additional relation between the involved masses and the applied magnetic field strength is fulfilled. Singularities and cusps in the pion mass dependence of the Delta(1232) electromagnetic moments reflect a non-fulfillment. We show results for the pion mass dependence of the nucleon iso-vector electromagnetic quantities and present results for finite volume effects on the iso-vector anomalous magnetic moment.Comment: 4 pages, 3 figures, prepared for Proceedings of the International Conference on the Structure of Baryons (BARYONS'10), Osaka, Japan, Dec. 7-11, 201