Do CDS spreads reflect default risks? Evidence from UK bank bailouts

CDS spreads are generally considered to reflect the credit risks of their reference entities. However, CDS spreads of the major UK banks remained relatively stable in response to the recent credit crisis. We suggest that this can be explained by changes in loss given default (LGD). To obtain the result we first derive the probabilities of default from stock option prices and then determine the LGD consistent with actual CDS spreads. Our results reveal a significant decrease in the LGD of bailed out banks over the observed period in contrast to banks which were not bailed out and non-financial companies

Tidal influence on self-potential measurements

DJM was supported by NERC CASE studentship NE/I018417/1. The authors would also like to thank Southern Water for access to the borehole at Saltdean. Atkins Global and Southern Water are thanked for funding installation of the equipment and for additional funding under the NERC studentship. The laboratory components of this work were carried out in the TOTAL Reservoir Physics Laboratory at Imperial College London and their support is gratefully acknowledged. Jackson acknowledges partial support from TOTAL under the TOTAL Chairs programme. The data supporting the conclusions of this work are available through the corresponding author.Peer reviewedPublisher PD

Belinfante Tensors Induced by Matter-Gravity Couplings

We show that any generally covariant coupling of matter fields to gravity gives rise to a conserved, on-shell symmetric energy-momentum tensor equivalent to the canonical energy-momentum tensor of the flat-space theory. For matter fields minimally coupled to gravity our algorithm gives the conventional Belinfante tensor. We establish that different matter-gravity couplings give metric energy-momentum tensors differing by identically conserved tensors. We prove that the metric energy-momentum tensor obtained from an arbitrary gravity theory is on-shell equivalent to the canonical energy-momentum tensor of the flat-space theory.Comment: 10 pages, LaTex; misprints corrected, references added; to appear in Physical Review

Low-temperature specific heat of real crystals: Possibility of leading contribution of optical and short-wavelength acoustical vibrations

We point out that the repeatedly reported glass-like properties of crystalline materials are not necessarily associated with localized (or quasilocalized) excitations. In real crystals, optical and short-wavelength acoustical vibrations remain damped due to defects down to zero temperature. If such a damping is frequency-independent, e.g. due to planar defects or charged defects, these optical and short-wavelength acoustical vibrations yield a linear-in-$T$ contribution to the low-temperature specific heat of the crystal lattices. At low enough temperatures such a contribution will prevail over that of the long-wavelength acoustical vibrations (Debye contribution). The crossover between the linear and the Debye regime takes place at $T^* \propto \sqrt N$, where $N$ is the concentration of the defects responsible for the damping. Estimates show that this crossover could be observable.Comment: 5 pages. v4: Error in Appendix corrected, which does not change the main results of the pape

Kinetics of Twinning and Dislocation Slip During Cyclic Deformation of ZK30 Magnesium Alloy

The present study clarifies the anisotropy of tension-compression behaviour during the cyclic deformation of ZK30 magnesium alloy. Some details of mechanical twinning and dislocation slip are studied by acoustic emission technique and direct video observations. Through the combination of these methods, the overall effect of deformation mechanisms is determined for each loading direction and their effect on the cyclic deformation is highlighted