CMB angular spectrum measurements suggest a flat universe. This paper clarifies the relation between geometry and the spherical harmonic index of the first acoustic peak (ℓ peak). Numerical and analytic calculations show that ℓ peak is approximately a function of Ω K /Ω M where Ω K and Ω M are the curvature (Ω K > 0 implies an open geometry) and mass density today in units of critical density. ...

We investigate the asymmetry of the scattering cross section of radiation around Lyα by atomic hydrogen, which may be applied to analyses of scattering media with high column neutral hydrogen densities including damped Lyα absorption systems of quasars. The exact scattering cross section is given by the Kramers-Heisenberg formula obtained from the fully quantum mechanical second-order time depe...

1 Problem In view of recent interest in orbital angular momentum modes in optical fibers, 1 discuss angular momentum in the modes of a circular waveguide of radius a, with perfectly conducting walls and filled with a medium of index of refraction n. 2 Solution Circular-waveguide modes were first discussed in 1893 by J.J. Thomson in sec. 300 of [2] and then by Rayleigh in 1897 [3]. 2 Although th...

We consider the transport of angular momentum in accretion disks that are low mass, in the sense that the gravitational forces produced by the material in these disks has a negligible effect on disk dynamics. There is no established consensus on how this transport takes place. We note that for phenomenological reasons the traditional α model is probably not a good description of real disks. Her...

let g be a locally compact group, and let ω be a weight on g. we show that the weightedmeasure algebra m(g,ω) is amenable if and only if g is a discrete, amenable group andsup{ω(g) ω(g−1) : g ∈ g} < ∞, where ω(g) ≥ 1 (g ∈ g) .

Assuming the existence of a spherically symmetric, self-similar solution of general relativity with matter that is locally an attractor of codimension one on the black hole threshold, we calculate the dependence of the black hole angular momentum on the initial data, near the black hole threshold and near spherical symmetry. As any smooth one-parameter family of initial data crosses the thresho...

Charged rotating black holes of Einstein-Maxwell-Chern-Simons theory in odd dimensions, D ≥ 5, may possess a negative horizon mass, while their total mass is positive. This surprising feature is related to the existence of counterrotating solutions, where the horizon angular velocity Ω and the angular momentum J possess opposite signs. Black holes may further possess vanishing horizon angular v...

Nomenclature C = chord length, m C T = thrust coefficient f = flapping frequency, Hz h tip = plunge amplitude at the wing tip, m k = ωC∕U ∞ , reduced frequency l span = wingspan, m Re = U ∞ C∕ν, Reynolds number r z = z-directional distance away from the wing tip, m S wing = wing area, m 2 St = fh tip ∕U ∞ , Strouhal number U ∞ = freestream velocity, m∕s ν = kinematic viscosity of fluid, m 2 ∕s ...

In this section we expand on the sinusoidal model derived in the to allow for arbitrary periodic modulation functions for both the illumination and the camera reference signal. As before, we assume periodically modulated illumination with an angular frequency ω. In the general case, this illumination signal can be described as a superposition of all the harmonics of this frequency at different ...

Introduction: Acute kidney injury (AKI) is a common postoperative complication of cardiac surgery, which is associated with an increased risk of morbidity and mortality. This study investigated the frequency of postoperative AKI in low risk adult patients undergoing off-pump coronary artery bypass grafting (CABG).Materials & Methods: All consecutive adult patients of American Society of Anesthe...