Nguyen Quynh Lan

Evolutionary Tracks for Betelgeuse

We have constructed a series of non-rotating quasi-hydrostatic evolutionary models for the M2 Iab supergiant Betelgeuse (

SPINNING DUST EMISSION FROM ULTRA-SMALL SILICATES: EMISSIVITY AND POLARIZATION SPECTRUM

\alpha~Orionis

Constraints on preinflation fluctuations in a nearly flat open Λ CDM cosmology

). Our models are constrained by multiple observed values for the temperature, luminosity, surface composition and mass loss for this star, along with the parallax distance and high resolution imagery that determines its radius. We have then applied our best-fit models to analyze the observed variations in surface luminosity and the size of detected surface bright spots as the result of up-flowing convective material from regions of high temperature in the surface convective zone. We also attempt to explain the intermittently observed periodic variability in a simple radial linear adiabatic pulsation model. Based upon the best fit to all observed data, we suggest a best progenitor mass estimate of

Ohmic currents and predecoupling magnetism

20 ^{+5}_{-3} M_\odot

Constraints on Early Star Formation and Mixing from Nucleosynthesis in Protogalactic clouds

and a current age from the start of the zero-age main sequence of

Analysis of the Conformally Flat Approximation for Binary Neutron Star Initial Conditions

8.0 - 8.5

ALTERNATIVE UNIFIED VIEWS ON DARK MATTER AND DARK ENERGY

Myr based upon the observed ejected mass while on the giant branch.

FORMULATION AND CONSTRAINTS ON LATE DECAYING DARK MATTER

Anomalous microwave emission (AME) is an important Galactic foreground of cosmic microwave background radiation. It is believed that AME arises from rotational emission by spinning polycyclic aromatic hydrocarbons in the interstellar medium (ISM). In this paper, we suppose that a new population of ultra-small silicate grains perhaps exists in the ISM, and quantify the rotational emissivity from these tiny particles and its polarization spectrum. We find that spinning silicate nanoparticles can produce strong rotational emission when the tiny grains follow a log-normal size distribution. The polarization fraction of spinning dust emission from tiny silicates increases with decreasing dipole moment per atom (β) and can reach for at a grain temperature of 60 K. We identify a parameter space , with being the fraction of Si abundance in nanoparticles, in which its rotational emission can adequately reproduce both the observed AME and the polarization of the AME, without violating the observational constraints of ultraviolet extinction and polarization of starlight. Our results reveal that rotational emission from spinning silicate may be an important source of AME.

ORIGIN AND EVOLUTION OF STRUCTURE FOR GALAXIES IN THE LOCAL GROUP

We analyze constraints on parameters characterizing the pre-inflating universe in an open inflation model with a present slightly open

CONSTRAINTS ON PRE-INFLATION COSMOLOGY AND DARK FLOW

\Lambda