A semi-infinite matrix analysis of the BFKL equation

The forward BFKL equation is discretised in virtuality space and it is shown that the diffusion into infrared and ultraviolet momenta can be understood in terms of a semi-infinite matrix. The square truncation of this matrix can be exponentiated leading to asymptotic eigenstates sharing many features with the BFKL gluon Green's function in the limit of large matrix size. This truncation is closely related to a representation of the XXX Heisenberg spin $= - \frac{1}{2}$ chain with SL(2) invariance where the Hamiltonian acts on a symmetric double copy of the harmonic oscillator. A simple modification of the BFKL matrix suppressing the infrared modes generates evolution with energy compatible with unitarity.Comment: Small changes, same conclusions, matching the published version in EPJ

Quasipolyhedral sets in linear semiinfinite inequality systems

AbstractThis paper provides an extension to linear semiinfinite systems of a well-known property of finite linear inequality systems, the so-called Weyl property, which characterizes the extreme points of the solution set as those solution points such that the gradient vectors of the active constraints form a complete set. A class of linear semiinfinite systems which satisfy this property is identified, the p-systems. It is also shown that any p-system contains an equivalent minimal subsystem

Stability of the Duality Gap in Linear Optimization

In this paper we consider the duality gap function g that measures the difference between the optimal values of the primal problem and of the dual problem in linear programming and in linear semi-infinite programming. We analyze its behavior when the data defining these problems may be perturbed, considering seven different scenarios. In particular we find some stability results by proving that, under mild conditions, either the duality gap of the perturbed problems is zero or + ∞ around the given data, or g has an infinite jump at it. We also give conditions guaranteeing that those data providing a finite duality gap are limits of sequences of data providing zero duality gap for sufficiently small perturbations, which is a generic result.This research was partially supported by MINECO of Spain and FEDER of EU, Grant MTM2014-59179-C2-01 and SECTyP-UNCuyo Res. 4540/13-R

Experiencias en el tratamiento para la enfermedad de Chagas en niños en edad escolar de Paraguay

Las referencias de trabajos sobre tratamiento en pacientes con la enfermedad de Chagas en nuestro país son escasas, y en especial en el grupo etario de niños de 6 a 12 años infectados con T. cruzi. El Instituto de Investigaciones en Ciencias de la Salud (IICS) llevó a cabo dos estudios de evaluación del tratamiento en niños en edad escolar tanto de zonas marginales de Asunción, como de zonas rurales. En ambos, se incluyó la evaluación basal, el tratamiento y la evaluación post-tratamiento en los niños que resultaron con serología positiva para anticuerpos anti-T. cruzi por IFI y ELISA a fin de cumplir con el criterio de infección. El tratamiento fue con benznidazol bajo estricta supervisión médica. Aunque no se presentó la negativización serológica en el 100% de las muestras, el panorama post-tratamiento que se obtuvo en estos niños en etapa crónica reciente de la enfermedad de Chagas fue la disminución significativa en la concentración de anticuerpos anti-T. cruzi y en otros, seroconversiones negativas. En el examen parasitológico se obtuvo negativización en ambos grupos y tolerancia a la medicación. Es importante destacar que con este tratamiento, se brinda la oportunidad de disminuir la aparición de lesiones cardíacas y digestivas en la edad adulta. A su vez se deben llevar a cabo acciones sostenidas de salud pública desde el nacimiento hasta la adolescencia, ya que en estas edades, se observa la mejor respuesta a los parasiticidas

Impact experiments in support of “Lithopanspermia”: The route from Mars to Earth

Shock recovery experiments on a Martian analogue rock (gabbro) loaded with three types of microorganisms reveal that these organisms survive the impact and ejection phase on Mars at shock pressures up to about 50 GPa with exponentially decreasing survival rates

Selected Applications of Linear Semi-Infinite Systems Theory

In this paper we, firstly, review the main known results on systems of an arbitrary (possibly infinite) number of weak linear inequalities posed in the Euclidean space Rn (i.e., with n unknowns), and, secondly, show the potential power of this theoretical tool by developing in detail two significant applications, one to computational geometry: the Voronoi cells, and the other to mathematical analysis: approximate subdifferentials, recovering known results in both fields and proving new ones. In particular, this paper completes the existing theory of farthest Voronoi cells of infinite sets of sites by appealing to well-known results on linear semi-infinite systems.This research was partially supported by PGC2018-097960-B-C22 of the Ministerio de Ciencia, Innovación y Universidades (MCIU), the Agencia Estatal de Investigación (AEI), and the European Regional Development Fund (ERDF); by CONICET, Argentina, Res D No 4198/17; and by Universidad Nacional de Cuyo, Secretaría de Investigación, Internacionales y Posgrado (SIIP), Res. 3922/19-R, Cod.06/D227, Argentina