Triaxial instabilities in rapidly rotating Neutron Stars

Viscosity driven bar mode secular instabilities of rapidly rotating neutron stars are studied using LORENE/Nrotstar code. These instabilities set a more rigorous limit to the rotation frequency of neutron star than the Kepler frequency/mass shedding limit. The procedure employed in the code comprises of perturbing an axisymmetric and stationary configuration of a neutron star and studying its evolution by constructing a series of triaxial quasi-equilibrium configurations. Symmetry breaking point was found out for Polytropic as well as 10 realistic Equations of states (EOS) from the CompOSE database. The concept of piecewise polytropic EOSs has been used to comprehend the rotational instability of Realistic EOSs and validated with 19 different Realistic EOSs from CompOSE. The possibility of detecting quasi-periodic gravitational waves from viscosity driven instability with ground based LIGO/VIRGO interferometers is also discussed very briefly.Comment: 12 pages, 17 figures, MNRAS (in press

On uniqueness of the Laplace transform on time scales

After introducing the concept of null functions, we shall present a uniqueness result in the sense of the null functions for the Laplace transform on time scales with arbitrary graininess. The result can be regarded as a dynamic extension of the well-known Lerch's theorem

How does the design of international environmental agreements affect investment in environmentally friendly technologies ?

This paper studies the link between the design of international environmental agreements and the incentives for the private sector to invest in cleaner technologies. More specifically, it compares the performance, in the Paretoo sense, of two types of agreement : an agreement on a uniform standard with transfers and an agreement on differentiated standards without transfers. To achieve this goal, we use a multi-stage game where the private sector anticipates its irreversible investment given the expected level of abatement standards, resulting from future bilateral negotiations. Our findings indicate that whenever countries are able to partially commit, the agreement on a uniform standard may be preferable, as it creates greater incentives for firms to invest in costly abatement technology. This result relies on the low level of the set-up cost of this technology. If this level is sufficiently high, the announcement and implementation of the agreement on a uniform standard with transfers is not optimal, because it takes away the incentive of all firms to invest in a new abatement technology.agreements, standards, transfers, technology adoption, irreversible investment, bargaining, transboundary pollution.