The Russian corporation: patterns of behavior during the crisis

This paper considers the behavior patterns of Russian firms before and during the financial crisis of 2008-2009. To facilitate comparison, we define three main groups of actors at the firm level in the Russian economy – large, politically connected companies; mid-size firms that expanded in the 2000s with the help of administrative support, and successful mid-size firms driven by market factors. Many of the large companies practiced highly risky financial policy and experienced a decrease in efficiency before the crisis, and the managers and owners of some Russian firms have been engaging in opportunistic behavior during the crisis; the forms and causes of this behavior are analyzed here. We conclude by proposing some policy implications with emphasis on supporting successful mid-size firms driven by market factors

Relative frequencies in multitype branching processes

This paper considers the relative frequencies of distinct types of individuals in multitype branching processes. We prove that the frequencies are asymptotically multivariate normal when the initial number of ancestors is large and the time of observation is fixed. The result is valid for any branching process with a finite number of types; the only assumption required is that of independent individual evolutions. The problem under consideration is motivated by applications in the area of cell biology. Specifically, the reported limiting results are of advantage in cell kinetics studies where the relative frequencies but not the absolute cell counts are accessible to measurement. Relevant statistical applications are discussed in the context of asymptotic maximum likelihood inference for multitype branching processes.Comment: Published in at http://dx.doi.org/10.1214/08-AAP539 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Direct Urca Process in a Neutron Star Mantle

We show that the direct Urca process of neutrino emission is allowed in two possible phases of nonspherical nuclei (inverse cylinders and inverse spheres) in the mantle of a neutron star near the crust-core interface. The process is open because neutrons and protons move in a periodic potential created by inhomogeneous nuclear structures. In this way the nucleons acquire large quasimomenta needed to satisfy momentum-conservation in the neutrino reaction. The appropriate neutrino emissivity in a nonsuperfluid matter is about 2--3 orders of magnitude higher than the emissivity of the modified Urca process in the stellar core. The process may noticeably accelerate the cooling of low-mass neutron stars.Comment: 7 pages, 3 figures, submitted to A&

Thermal Evolution of a Pulsating Neutron Star

We have derived a set of equations to describe the thermal evolution of a neutron star which undergoes small-amplitude radial pulsations. We have taken into account, in the frame of the General Theory of Relativity, the pulsation damping due to the bulk and shear viscosity and the accompanying heating of the star. The neutrino emission of a pulsating non-superfluid star and its heating due to the bulk viscosity are calculated assuming that both processes are determined by the non-equilibrium modified Urca process. Analytical and numerical solutions to the set of equations of the stellar evolution are obtained for linear and strongly non-linear deviations from beta-equilibrium. It is shown that a pulsating star may be heated to very high temperatures, while the pulsations damp very slowly with time (a power law damping for 100-1000 years), as long as the damping is determined by the bulk viscosity. The contribution of the shear viscosity to the damping becomes important in a rather cool star with a low pulsation energy.Comment: 10 pages, 3 figures, an important reference to the paper by Finzi & Wolf (1968) is added; analytical consideration of the problem (Section 5) is essentially extende

Three Types of Cooling Superfluid Neutron Stars: Theory and Observations

Cooling of neutron stars (NSs) with the cores composed of neutrons, protons, and electrons is simulated assuming $^1$S$_0$ pairing of neutrons in the NS crust, and also $^1$S$_0$ pairing of protons and weak $^3$P$_2$ pairing of neutrons in the NS core, and using realistic density profiles of the superfluid critical temperatures $T_{\rm c}(\rho)$. The theoretical cooling models of isolated middle-aged NSs can be divided into three main types. (I) {\it Low-mass}, {\it slowly cooling} NSs where the direct Urca process of neutrino emission is either forbidden or almost fully suppressed by the proton superfluidity. (II) {\it Medium-mass} NSs which show {\it moderate} cooling via the direct Urca process suppressed by the proton superfluidity. (III) {\it Massive} NSs which show {\it fast} cooling via the direct Urca process weakly suppressed by superfluidity. Confronting the theory with observations we treat RX J0822--43, PSR 1055--52 and RX J1856--3754 as slowly cooling NSs. To explain these sufficiently warm sources we need a density profile $T_{\rm c}(\rho)$ in the crust with a rather high and flat maximum and sharp wings. We treat 1E 1207--52, RX J0002+62, PSR 0656+14, Vela, and Geminga as moderately cooling NSs. We can determine their masses for a given model of proton superfluidity, $T_{\rm cp}(\rho)$, and the equation of state in the NS core. No rapidly cooling NS has been observed so far.Comment: 12 pages, 10 figures, Astron. Astrophys., submitte

Equation of state of classical Coulomb plasma mixtures

We develop analytic approximations of thermodynamic functions of fully ionized nonideal electron-ion plasma mixtures. In the regime of strong Coulomb coupling, we use our previously developed analytic approximations for the free energy of one-component plasmas with rigid and polarizable electron background and apply the linear mixing rule (LMR). Other thermodynamic functions are obtained through analytic derivation of this free energy. In order to obtain an analytic approximation for the intermediate coupling and transition to the Debye-Hueckel limit, we perform hypernetted-chain calculations of the free energy, internal energy, and pressure for mixtures of different ion species and introduce a correction to the LMR, which allows a smooth transition from strong to weak Coulomb coupling in agreement with the numerical results.Comment: 6 pages, 7 figures; Phys. Rev. E. In v.2 after proofreading, minor typos are fixe