Barnett, Ryan Demler, Eugene Kaxiras, Efthimios

We perform analysis of the band structure, phonon dispersion, and electron-phonon interactions in three types of small-radius carbon nanotubes. We find that the (5,5) can be described well by the zone-folding method and the electron-phonon interaction is too small to support either a charge-density wave or superconductivity at realistic temperature...

Trotta, Roberto Melchiorri, Alessandro

We demonstrate that combining Cosmic Microwave Background anisotropy measurements from the 1st year WMAP observations with clustering data from the SLOAN galaxy redshift survey yields an indication for primordial anisotropies in the cosmological Neutrino Background.

Holm, Darryl D. Putkaradze, Vakhtang

New model equations are derived for dynamics of self-aggregation of finite-size particles. Differences from standard Debye-Huckel and Keller-Segel models are: the mobility of particles depends on the configuration of their neighbors and linear diffusion acts on locally-averaged particle density. The evolution of collapsed states in these models red...

Fabijonas, Bruce R. Holm, Darryl D.

We examine the effects of turbulence on elliptic instability of rotating stratified incompressible flows, in the context of the Lagragian-averaged Euler-Boussinesq-alpha, or \laeba, model of turbulence. We find that the \laeba model alters the instability in a variety of ways for fixed Rossby number and Brunt-V\"ais\"al\"a frequency. First, it alte...

Lehners, JL Smyth, P Stelle, KS

Hořava–Witten spacetimes necessarily include two branes of opposite tension. If these branes are BPS we are led to a puzzle: a negative tension brane should be unstable as it can lose energy by expanding, whereas a BPS brane should be stable as it resides at a minimum of the energy. We provide a detailed analysis of the energy of such braneworld sp...

Graham, J. Pietarila Holm, D. D. Mininni, P. Pouquet, A.

We present an extension of the Karman-Howarth theorem to the Lagrangian averaged magnetohydrodynamic (LAMHD-alpha) equations. The scaling laws resulting as a corollary of this theorem are studied in numerical simulations, as well as the scaling of the longitudinal structure function exponents indicative of intermittency. Numerical simulations for a...

Barnett, Ryan Polkovnikov, Anatoli Demler, Eugene Yin, Wei-Guo Ku, Wei

An unexpected feature common to 2H-transition metal dichalcogenides (2H-TMDs) is revealed with first-principles Wannier functions analysis of the electronic structure of the prototype 2H-TaSe2: The low-energy Ta \red{``$5d_{z^2}$''} bands governing the physics of charge-density wave (CDW) is dominated by hopping between next-nearest neighbors. With...

Warnick, Claude

The semi-classical stability of several AdS NUT instantons is studied. Throughout, the notion of stability is that of stability at the one-loop level of Euclidean Quantum Gravity. Instabilities manifest themselves as negative eigenmodes of a modified Lichnerowicz Laplacian acting on the transverse traceless perturbations. An instability is found fo...

de Austri, Roberto Ruiz Trotta, Roberto Roszkowski, Leszek

We perform a comprehensive exploration of the Constrained MSSM parameters using a Markov Chain Monte Carlo technique and a Bayesian analysis. We compute superpartner masses and other collider observables as well as a cold dark matter abundance, and compare them with experimental data. We include uncertainties arising from theoretical approximations...

Barnett, Ryan Petrov, Dmitry Lukin, Mikhail Demler, Eugene

We consider bosonic dipolar molecules in an optical lattice prepared in a mixture of different rotational states. The 1/r^3 interaction between molecules for this system is produced by exchanging a quantum of angular momentum between two molecules. We show that the Mott states of such systems have a large variety of non-trivial spin orderings inclu...