BRST quantization of gauge theories like SL(2,R) on inner product spaces

Some general formulas are derived for the solutions of a BRST quantization on inner product spaces of finite dimensional bosonic gauge theories invariant under arbitrary Lie groups. A detailed analysis is then performed of SL(2,R) invariant models and some possible geometries of the Lagrange multipliers are derived together with explicit results for a class of SL(2,R) models. Gauge models invariant under a nonunimodular gauge group are also studied in some detail.Comment: 20 pages,latexfil

Lepton-pair Cerenkov radiation emitted by tachyonic neutrinos: Lorentz-covariant approach and IceCube data

Current experiments do not exclude the possibility that one or more neutrinos are very slightly superluminal or that they have a very small tachyonic mass. Important bounds on the size of a hypothetical tachyonic neutrino mass term are set by lepton pair Cerenkov radiation (LPCR), i.e., by the decay channel nu -> e^+ e^- nu which proceeds via a virtual Z0 boson. Here, we use a Lorentz-invariant dispersion relation which leads to very tight constraints on the tachyonic mass of neutrinos; we also calculate decay and energy loss rates. A possible cutoff seen in the IceCube neutrino spectrum for E_nu > 2 PeV, due to the potential onset of LPCR, is discussed.Comment: 7 pages; accepted for publication in the Advances of High-Energy Physic

Ownership and control in joint ventures: theory and evidence

Joint ventures, a particularly popular form of corporate cooperation, exhibit ownership patterns that are clustered around equal shareholdings for a wide variety of parent firms. In this paper, we investigate why 50-50 or "50 plus one share" equity allocations should be so prevalent. In our model, parent firms trade off control benefits and costs with incentives for resource contributions in the presence of asset complementarities. We show that strict resource complementarity eliminates moral hazard in parent contributions so that ownership provides sufficient incentives for optimal investments. However, the potential for extraction of residual control benefits by the majority owner creates a discontinuity in contribution incentives at 50% equity stakes that explains the optimal clustering of ownership around 50-50 shareholdings. Using data from 1,248 US joint ventures announced between 1985 and 2000, we empirically analyze the determinants of their ownership allocations and conduct tests of model predictions that offer strong support for our theory.joint ventures; partnerships; ownership; asset complementarity; buyout options

Self tolerance in a minimal model of the idiotypic network

We consider the problem of self tolerance in the frame of a minimalistic model of the idiotypic network. A node of this network represents a population of B lymphocytes of the same idiotype which is encoded by a bit string. The links of the network connect nodes with (nearly) complementary strings. The population of a node survives if the number of occupied neighbours is not too small and not too large. There is an influx of lymphocytes with random idiotype from the bone marrow. Previous investigations have shown that this system evolves toward highly organized architectures, where the nodes can be classified into groups according to their statistical properties. The building principles of these architectures can be analytically described and the statistical results of simulations agree very well with results of a modular mean field theory. In this paper we present simulation results for the case that one or several nodes, playing the role of self, are permanently occupied. We observe that the group structure of the architecture is very similar to the case without self antigen, but organized such that the neighbours of the self are only weakly occupied, thus providing self tolerance. We also treat this situation in mean field theory which give results in good agreement with data from simulation.Comment: 7 pages, 6 figures, 1 tabl

Thermodynamic anomalies in the presence of dissipation: from the free particle to the harmonic oscillator

A free particle coupled to a heat bath can exhibit a number of thermodynamic anomalies like a negative specific heat or reentrant classicality. These low-temperature phenomena are expected to be modified at very low temperatures where finite-size effects associated with the discreteness of the energy spectrum become relevant. In this paper, we explore in which form the thermodynamic anomalies of the free damped particle appear for a damped harmonic oscillator. Since the discreteness of the oscillator's energy spectrum is fully accounted for, the results are valid for arbitrary temperatures. As expected, they are in agreement with the third law of thermodynamics and indicate how the thermodynamic anomalies of the free damped particle can be reconciled with the third law. Particular attention is paid to the transition from the harmonic oscillator to the free particle when the limit of the oscillator frequency to zero is taken.Comment: 10 pages, 5 figure

A CGE-Analysis of Energy Policies Considering Labor Market Imperfections and Technology Specifications

The paper establishes a CGE/MPSGE model for evaluating energy policy measures with emphasis on their employment impacts. It specifies a dual labor market with respect to qualification, two different mechanisms for skill specific unemployment, and a technology detailed description of electricity generation. Non clearing of the dual labor market is modeled via minimum wage constraints and via wage curves. The model is exemplarily applied for the analysis of capital subsidies on the application of technologies using renewable energy sources. Quantitative results highlight that subsidies on these technologies do not automatically lead to a significant reduction in emissions. Moreover, if emission reductions are achieved these might actually partly result from negative growth effects induced by the promotion of cost inefficient technologies. Inefficiencies in the energy system increase unemployment for both skilled and unskilled labor.CGE, Energy Economic Analysis, Employment Impact, Choice of Technology