Operator splitting for the Benjamin-Ono equation

In this paper we analyze operator splitting for the Benjamin-Ono equation, u_t = uu_x + Hu_xx, where H denotes the Hilbert transform. If the initial data are sufficiently regular, we show the convergence of both Godunov and Strang splitting.Comment: 18 Page

Neutrino Mass and Grand Unification

Seesaw mechanism appears to be the simplest and most appealing way to understand small neutrino masses observed in recent experiments. It introduces three right handed neutrinos with heavy masses to the standard model, with at least one mass required by data to be close to the scale of conventional grand unified theories. This may be a hint that the new physics scale implied by neutrino masses and grand unification of forces are one and the same. Taking this point of view seriously, I explore different ways to resolve the puzzle of large neutrino mixings in grand unified theories such as SO(10) and models based on its subgroup $SU(2)_L\times SU(2)_R\times SU(4)_c$.Comment: 17 pages, 5 figures; Invited talk at the Nobel Symposium 129 on Neutrinos at Haga Slott, Sweden, August, 200

CP Asymmetries in B to f_0 K_S Decays

We consider the branching ratio and the CP asymmetries in B to f_0(980)K_S decay to the end of determining the deviation of the time-dependent CP asymmetry from sin(2 beta) arising from Standard Model physics. We obtain Delta S_{f_0 K_S} within the context of the QCD factorization framework for the B to f_0(980)K_S decay amplitudes assuming the f_0(980) is a q\bar{q} state and employing a random scan over the theoretical parameter space to assess the possible range in Delta S_{f_0 K_S}. Imposing the value of the experimental branching ratio within 1 sigma and 3 sigma, respectively, of its central value as a constraint, we find the range of Delta S_{f_0 K_S} to be [0.018, 0.033] for a scan in which the parameters are allowed to vary within 1 sigma of their central values and the range [-0.019, 0.064] for a scan in which the parameters vary within 3 sigma of their central values.Comment: 27 pages, 10 figures, references adde

Semi-classical equation of state and specific heats for neutron-star inner crust with proton shell corrections

An approach to the equation of state for the inner crust of neutron stars based on Skyrme-type forces is presented. Working within the Wigner-Seitz picture, the energy is calculated by the TETF (temperature-dependent extended Thomas-Fermi) method, with proton shell corrections added self-consistently by the Strutinsky-integral method. Using a Skyrme force that has been fitted to both neutron matter and to essentially all the nuclear mass data, we find strong proton shell effects: proton numbers $Z$ = 50, 40 and 20 are the only values possible in the inner crust, assuming that nuclear equilibrium is maintained in the cooling neutron star right down to the ambient temperature. Convergence problems with the TETF expansion for the entropy, and our way of handling them, are discussed. Full TETF expressions for the specific heat of inhomogeneous nuclear matter are presented. Our treatment of the electron gas, including its specific heat, is essentially exact, and is described in detail.Comment: 41 pages, 6 figure

Struggling to a monumental triumph : Re-assessing the final stages of the smallpox eradication program in India, 1960-1980

The global smallpox program is generally presented as the brainchild of a handful of actors from the WHO headquarters in Geneva and at the agency's regional offices. This article attempts to present a more complex description of the drive to eradicate smallpox. Based on the example of India, a major focus of the campaign, it is argued that historians and public health officials should recognize the varying roles played by a much wider range of participants. Highlighting the significance of both Indian and international field officials, the author shows how bureaucrats and politicians at different levels of administration and society managed to strengthen—yet sometimes weaken—important program components. Centrally dictated strategies developed at WHO offices in Geneva and New Delhi, often in association with Indian federal authorities, were reinterpreted by many actors and sometimes changed beyond recognition

Phase transitions in periodically driven macroscopic systems

We study the large-time behavior of a class of periodically driven macroscopic systems. We find, for a certain range of the parameters of either the system or the driving fields, the time-averaged asymptotic behavior effectively is that of certain other equilibrium systems. We then illustrate with a few examples how the conventional knowledge of the equilibrium systems can be made use in choosing the driving fields to engineer new phases and to induce new phase transitions.Comment: LaTex, 8 page

Numerical modelling of dissipation energy of high tensile steel frames against cyclic earthquake excitations

The design of steel structures for ductile response requires (a) materialductility, (b) cross section and member ductility, and (c) structural ductility. Dissipating the earthquake input energy by means of plastic excursions has to be compatible with the plastic deformation capacity of the structure. This work concerns incremental approach of modeling for elastoplastic analysis of structural members subjected to harmonically varying severe earthquake loads and their parametric responses over a range of applied frequencies and amplitudes. Investigations have been carried out in respect of stable and reliable hysteretic energy dissipation mechanisms of high rise steel structures against typical time-history loading of four hypothetical frequencies. Eigen-buckling responses for high rise steel structures subjected to earthquake forces are derived using general purpose software (STAAD). Finally critical structural component is identified for the high rise steel structure for estimation of available in-elastic dissipation energy from material ductility against earthquake excitations. The novelty allows for a very useful generalized formulation for the basic analysis procedures adopted in non-linear material problems. All essential features of a non-linear finite element solution are described in relation to one dimensional model for elasto-plastic beam bending. Solutions techniques are programmed in FORTRAN 90 for Newton-Raphson iteration for non-linear finite element analysis to derive hysteretic energy dissipation of high rise steel structures