Unconventional superconductivity in iron-base superconductors in a three-band model

Iron-base superconductors exhibits features of systems where the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) phase, a superconducting state with non-zero total momentum of Cooper pairs, is actively sought. Experimental and theoretical evidence points strongly to the FFLO phase in these materials above the Pauli limit. In this article we discuss the ground state of iron-base superconductors near the critical magnetic field and the full $h-T$ phase diagram for pnictides in case of intra-band pairing, in a three-band model with $s_{\pm}$ symmetry.Comment: RevTeX, 5 pages, 3 figures. Presented on "XVI National Conference of Superconductivity", October 7-12, 2013, Zakopane, Polan

Nationalizations and effciency

We develop a theoretical model in which ?rms are either private or state-owned. When ?rms become insolvent, the government can intervene with general measures, like subsidies, or by nationalizing ?rms. The government only intervenes when the bankruptcy of a ?rm entails social costs. In a stylized model, we analyze how government interventions a?ect allocative and productive efficiency. Nationalization of private ?rms in case unpro?table investments were made, leads to increased allocative efficiency despite private ownership. The effort level chosen by the managers working for ?rms is also affected by government intervention with an impact on productive efficiency

Size and soft budget constraints

There is much evidence against the so-called "too big to fail" hypothesis in the case of bailouts to sub-national governments. We look at a model where districts of different size provide local public goods with positive spillovers. Matching grants of a central government can induce socially-efficient provision, but districts can still exploit the intervening central government by inducing direct financing. We show that the ability of a district to induce a bailout from the central government and district size are negatively correlated

Optical trapping of anti-hydrogen towards an atomic anti-clock

The Anti-Matter Factory at CERN is gearing up, commissioning of the Extra Low ENergy Antiprotons (ELENA) ring is ongoing and the first anti-protons are foreseen to circulate in the decelerator very soon. The unprecedented flux of low energy antiprotons delivered by ELENA will open a new era for precision tests with antimatter including laser and microwave spectroscopy and tests of its gravitational behaviour. Here we propose a scheme to load the ultra cold anti-hydrogen atoms that will be produced by the GBAR experiment in an optical lattice tuned at the magic wavelength of the 1S-2S transition in order to measure this interval at a level comparable or even better than its matter counter part. This will provide the most sensitive test of CPT symmetry parametrised in the framework of the Standard Model Extension.Comment: 7 pages, 2 Figure

Size and Soft Budget Constraints

There is much evidence against the so-called "too big to fail" hypothesis in the case of bailouts to sub-national governments. We look at a model where districts of different size provide local public goods with positive spillovers. Matching grants of a central government can induce socially-efficient provision, but districts can still exploit the intervening central government by inducing direct financing. We show that the ability of a district to induce a bailout from the central government and district size are negatively correlated.bailouts, soft-budget constraints, jurisdictional size, public goods, spillovers

Size and Soft Budget Constraints

There is much evidence against the so-called "too big to fail" hypothesis in the case of bailouts to sub-national governments. We look at a model where districts of di_erent size provide local public goods with positive spillovers. Matching grants of a central government can induce socially-e_cient provision, but districts can still exploit the intervening central government by inducing direct _nancing. We show that the ability of a district to induce a bailout from the central government and district size are negatively correlated.bailouts, soft-budget constraints, jurisdictional size, public goods, spillovers

Nationalizations and effciency

We develop a theoretical model in which ?rms are either private or state-owned. When ?rms become insolvent, the government can intervene with general measures, like subsidies, or by nationalizing ?rms. The government only intervenes when the bankruptcy of a ?rm entails social costs. In a stylized model, we analyze how government interventions a?ect allocative and productive efficiency. Nationalization of private ?rms in case unpro?table investments were made, leads to increased allocative efficiency despite private ownership. The effort level chosen by the managers working for ?rms is also affected by government intervention with an impact on productive efficiency.nationalization; efficiency

Energy current and energy fluctuations in driven quantum wires

We discuss the energy current and the energy fluctuations in an isolated quantum wire driven far from equilibrium. The system consists of interacting spinless fermions and is driven by a time--dependent magnetic flux. The energy current is defined by the continuity equation for the energy density which is derived both for homogeneous as well as for inhomogeneous systems. Since the total energy is not conserved in the driven system, the continuity equation includes the source terms which are shown to represent the Joule heating effects. For short times and weak drivings the energy current agrees with the linear response theory. For stronger fields or longer times of driving the system enters the quasiequilibrium regime when the energy current gradually diminishes due to the heating effects. Finally, for even stronger driving the energy current is shown to undergo a damped Bloch oscillations. The energy spread also increases upon driving. However, the time--dependence of this quantity in the low field regime is quite unexpected since it is determined mostly by the time of driving being quite independent of the instantaneous energy of the system.Comment: 9 pages, 2 figures, Proc. NATO Adv. Research Workshop Nanotechnology in the security systems, Ed. S. Kruchinin, Yalta, Ukraine, 201