We consider the production of gravitons in an inflationary cosmology by approximating each epoch of change in the equation of state as sudden, from which a simple analytic graviton mode function has been derived. We use this mode function to compute the graviton spectral energy density and the tensor-induced cosmic microwave background anisotropy. The results are then compared to the numerical ...

The measurements of CMB anisotropy have opened up a window for probing the global topology of the universe on length scales comparable to and beyond the Hubble radius. For compact topologies, the two main effects on the CMB are: (1) the breaking of statistical isotropy in characteristic patterns determined by the photon geodesic structure of the manifold and (2) an infrared cutoff in the power ...

The bers produced by co-evaporation of C 60 and potassium, and subsequent treatment in toluene, have been investigated by electron microscopy and optical spectroscopy. The electron diiraction pattern can be indexed in terms of the known orthorhombic (KC 60) n structure. The frequencies of the vibrational modes indicate charge transfer between the K and the C 60 , similar to bulk samples; no ani...

The lipid composition of archaea is unique and has been correlated with increased stability under extreme environmental conditions. In this article, we have focused on the evolution of membrane organization and dynamics with natural evolution. Dynamic anisotropy along the membrane normal (i.e., gradients of mobility, polarity, and heterogeneity) is a hallmark of fluid phase diester or diether p...

Cosmological inhomogeneities gravitationally deflect radiation propagating from distant sources, transforming the spatial and angular correlation functions of intrinsic source properties. For a gaussian distribution of deflections (e.g. from a primordial gaussian density perturbation spectrum or from the central limit theorem) we calculate the probability distributions for geodesic deviations. ...

Data Two data sets were tested : the first one consisted of older normal mode splitting measurements (1, 2) (with 15 degree two and 7 degree four structure coefficients), and the second one consisted of the most recent splitting measurements that followed the great Bolivia and Kuril Islands earthquakes in 1994 (3–5) (with 22 degree two and 16 degree four data). The choice of data set one was ba...

The development of a preferred crystallographic orientation in the plane of growth, an in-plane texture, is addressed in a model that incorporates anisotropic growth rates of a material and self-shadowing. Most crystalline materials exhibit fast growth along certain crystallographic directions and slow growth along others. This crystallographic growth anisotropy, which may be due to differences...

INTRODUCTION The supertoroid-based representation of cardiac DT-MRI was previously shown to enhance cardiac myofiber structure characterization compared to ellipsoids, superquadrics and toroids [1]. The supertoroidal model is an evolution of the toroid-based representation and provides a new index of diffusivity the toroidal volume (TV) [2,3] and a new coefficient of anisotropy the toroidal cur...

This paper presents a visualization and analysis framework for evaluating changes in structural organization of fiber bundles in human brain white matter. Statistical analysis of fiber bundle organization is conducted using an anisotropy measure, volume ratio (VR), which is ratio of anisotropic and isotropic components. Initially fiber bundles are tracked using a probabilistic algorithm startin...

BACKGROUND AND PURPOSE Hypertension is associated with the development of white matter lesions in older people. Diffusion tensor MRI can detect subtle, previsible white matter damage, but relationships between diffusion tensor MRI parameters and blood pressure (BP) remain unclear. We examined correlations among mean diffusivity (MD), fractional anisotropy and BP in 45 men aged 71 to 76 years. ...