Equation-of-state model for shock compression of hot dense matter

A quantum equation-of-state model is presented and applied to the calculation of high-pressure shock Hugoniot curves beyond the asymptotic fourfold density, close to the maximum compression where quantum effects play a role. An analytical estimate for the maximum attainable compression is proposed. It gives a good agreement with the equation-of-state model

Markets and operations: 2010 Q2

This article reviews developments in sterling financial markets since the 2010 Q1 Quarterly Bulletin up to 21 May 2010. The article also reviews the Bank’s official operations.

Observational Evidence of the Accelerated Expansion of the Universe

The discovery of cosmic acceleration is one of the most important developments in modern cosmology. The observation, thirteen years ago, that type Ia supernovae appear dimmer that they would have been in a decelerating universe followed by a series of independent observations involving galaxies and cluster of galaxies as well as the cosmic microwave background, all point in the same direction: we seem to be living in a flat universe whose expansion is currently undergoing an acceleration phase. In this paper, we review the various observational evidences, most of them gathered in the last decade, and the improvements expected from projects currently collecting data or in preparation.Comment: Accepted review article to appear in a special volume of the "Comptes Rendus de l'Acad\'emie des Sciences" about Dark Energy and Dark Matte

Resistivity in warm dense plasmas beyond the average-atom model

The exploration of atomic properties of strongly coupled partially degenerate plasmas, also referred to as warm dense matter, is important in astrophysics, since this thermodynamic regime is encountered for instance in Jovian planets' interior. One of the most important issues is the need for accurate equations of state and transport coefficients. The Ziman formula has been widely used for the computation of the static (DC) electrical resistivity. Usually, the calculations are based on the continuum wavefunctions computed in the temperature and density-dependent self-consistent potential of a fictive atom, representing the average ionization state of the plasma (average-atom model). We present calculations of the electrical resistivity of a plasma based on the superconfiguration (SC) formalism. In this modeling, the contributions of all the electronic configurations are taken into account. It is possible to obtain all the situations between the two limiting cases: detailed configurations (a super-orbital is a single orbital) and detailed ions (all orbitals are gathered in the same super-orbital). The ingredients necessary for the calculation are computed in a self-consistent manner for each SC, using a density-functional description of the electrons. Electron exchange-correlation is handled in the local-density approximation. The momentum transfer cross-sections are calculated by using the phase shifts of the continuum electron wavefunctions computed, in the potential of each SC, by the Schroedinger equation with relativistic corrections (Pauli approximation). Comparisons with experimental data are also presented.Comment: submitted to "Contributions to Plasma Physics

Markets and operations 2009 Q4

This article reviews developments in sterling financial markets since the 2009 Q3 Quarterly Bulletin up to end-November 2009. The article also reviews the Bank’s official operations.

Pain

Painkilling drugs produce a good called relief which reduces the fixed level of bad (pain) the individual is endowed with. These drugs have the side-effect of reducing the utility the individual gets from consuming goods. This means that the shadow price of relief counts not only the cost of drugs and their ability to reduce pain, but also the undesired reduction in pleasure from consuming goods. The tradeoff between goods and relief is non-linear and convex even for painkilling drugs that have a linear effect on pain. Small increases in pain may push the individual to a corner where painkilling drugs dominate his life. This seeming dependence on the drug has nothing to do with addiction or habit formation, but is a consequence of how consumption of these drugs changes the shadow prices of goods and relief.Pain, addiction, drugs, household production