In Ray-Tomography the goal is to recover a function in higher dimensions from knowledge of integrals of the function along lines. For example, in the Euclidean setting we let f ∈ C∞ 0 (R), and for each straight line L in R, we define the Ray-Transform of f along L as

In this study, use of a helical orbit in performing a long object SPECT scan with parallel, cone, fan, rotated fan, varying focal-length cone, divergent, and astigmatic collimators is proposed. Sufficient-data scanning helical orbits for these collimation geometries are developed. Both singledetector system and multi-detector system are considered. In order to verify our orbit design requiremen...

One of the principal goals of the quasar investigations is to study luminosity evolution. A convenient one-parameter model for luminosity says that the expected log luminosity, T ∗, increases linearly as θ0 · log(1+ Z∗), and T ∗(θ0) = T ∗ − θ0 · log(1 + Z∗) is independent of Z∗, where Z∗ is the redshift of a quasar and θ0 is the true value of evolution parameter. Due to experimental constraints...

We compute the asymptotical growth rate of a large family of Uq.sl2/ 6j –symbols and we interpret our results in geometric terms by relating them to volumes of hyperbolic truncated tetrahedra. We address a question which is strictly related with S Gukov’s generalized volume conjecture and deals with the case of hyperbolic links in connected sums of S S . We answer this question for the infinite...