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Little is known about the behaviour of the Oka property of a complex manifold with respect to blowing up a submanifold. A manifold is of Class A if it is the complement of an algebraic subvariety of codimension at least 2 in an algebraic manifold that is Zariski-locally isomorphic to C n. A manifold of Class A is algebraically subelliptic and hence Oka, and(More)
— Imaging processes built on the Compton scattering effect are currently under intense investigation. However, despite many innovative contributions, this topic still pose a formidable mathematical and technical challenge. In this work, we argue that, in the framework of single-photon emission imaging, collecting Compton scattered radiation from an emitting(More)
For a q × q matrix x = (x i,j) we let J(x) = (x −1 i,j) be the Hadamard inverse, which takes the reciprocal of the elements of x. We let I(x) = (x i,j) −1 denote the matrix inverse, and we define K = I • J to be the birational map obtained from the composition of these two involutions. We consider the iterates K n = K • · · · • K and determine degree(More)
In his seminal work of 1981, A M Cormack has established that Radon transforms defined on two remarkable families of curves in the plane are invertible and admit explicit inversion formulas via circular harmonic decomposition. A sufficient condition for finding larger classes of curves enjoying the same property is given in this paper. We show that these(More)
Let K be an algebraically closed field, X a smooth projective variety over K and f : X → X a dominant regular morphism. Let N i (X) be the group of algebraic cycles modulo numerical equivalence. Let χ(f) be the spectral radius of the pullback f * : H * (X, Q l) → H * (X, Q l) on l-adic cohomology groups, and λ(f) the spectral radius of the pullback f * : N(More)
We obtain some two-bound estimates for the local growth of pluri-subharmonic functions. We propose a conjecture which is similar to the comparison theorem in [H. Alexander and B. A. Taylor, Comparison of two capacities in C n , Math. Z. 186 (1984), 407–417]. We verify this conjecture in several cases. We then show that this conjecture implies extensions of(More)
We study the competitive action of magnetic field, Coulomb repulsion and space curvature on the motion of a charged particle. The three types of interaction are characterized by three basic lengths: lB the magnetic length, l0 the Bohr radius and R the radius of the sphere. The energy spectrum of the particle is found by solving a Schrödinger equation of the(More)