Heavy ion collisions at intermediate energies in a quark-gluon exchange framework

Heavy ion collisions at intermediate energies can be studied in the context of the Vlasov-Uehling-Uhlenbeck (VUU) model. One of the main features in this model is the nucleon-nucleon (NN) cross section in the collisional term. Quark interchange plays a role in the NN interaction and its effect can be observed in the cross section. We explore the possibility that quark interchange effects can appear in observables at energies lower than RHIC.Comment: To appear in the Proceedings of VIII Hadron Physics 200

Can quark effects be observed in intermediate heavy ion collisions?

In recent years a tentative description of the short-range part of hadron interactions with constituent quark interchange has been developed providing an alternative approach to meson physics. Quark interchange plays a role, for example, in the nucleon-nucleon ($NN$) phase-shifts and cross-section. In heavy ion collision simulations at intermediate energies one of the main features is the $NN$ cross-section in the collisional term, where in most cases it is an input adjusted to the free space value. In this paper we introduce the quark degrees of freedom to the $NN$ cross-section in the Vlasov-Uehling-Uhlenbeck (VUU) model and explore the possibility that these effects appear in the observables at lower energies.Comment: To appear in J. Phys. G: Nucl. Phy

Ressonant elliptic problems under Cerami condition

We establish existence and multiplicity of solutions for a elliptic resonant elliptic problem under Dirichlet boundary conditions.Comment: This is a research to resonant elliptic problems under Cerami condition using variational method

EROs in the EIS Fields. I: The AXAF (Chandra) Deep Field

The publicly available EIS-DEEP optical-NIR data for the AXAF (Chandra) Deep Field have been used to construct samples of Extremely Red Objects (EROs) using various single-band and multi-band color criteria. In this work we define as EROs objects with colors consistent with passively evolving elliptical galaxies at z $\geq$ 1. The EROs surface densities we derive are intermediate between previous published values, emphasizing again the need for larger survey areas to constrain the effects of possible large-scale structure. Although various single-color selected samples can be derived, the EROs sample selected using R-Ks > 5, I-Ks > 4, J-Ks > 1.8 jointly is likely to contain the highest fraction of passively evolving luminous field elliptical galaxies at z >= 1, or conversely, the lowest fraction of lower redshift interlopers. The surface density of this multi-band selected EROs sample is consistent with the conclusion that little or no field elliptical volume density evolution has occurred in the redshift range 0 > z > 1.5. However, extensive spectroscopic followup is necessary to confirm this conclusion.Comment: 8 pages, 4 figures. Accepted for publication in A&

Artin algebras of finite type and finite categories of Δ\Delta-good modules

We give an alternative proof to the fact that if the square of the infinite radical of the module category of an Artin algebra is equal to zero then the algebra is of finite type by making use of the theory of postprojective and preinjective partitions. Further, we use this new approach in order to get a characterization of finite subcategories of $\Delta$-good modules of a quasi-hereditary algebra in terms of depth of morphisms similar to a recently obtained characterization of Artin algebras of finite type.Comment: accepted for publication in Communications in Algebr

Multiplicity of solutions for gradient systems under strong resonance at the first eigenvalue

In this paper we establish existence and multiplicity of solutions for an elliptic system which has strong resonance at first eigenvalue. To describe the resonance, we use an eigenvalue problem with indefinite weight. In all results we use Variational Methods

Characterization of manifolds of constant curvature by spherical curves

It is known that the so-called rotation minimizing (RM) frames allow for a simple and elegant characterization of geodesic spherical curves in Euclidean, hyperbolic, and spherical spaces through a certain linear equation involving the coefficients that dictate the RM frame motion (da Silva, da Silva in Mediterr J Math 15:70, 2018). Here, we shall prove the converse, i.e., we show that if all geodesic spherical curves on a Riemannian manifold are characterized by a certain linear equation, then all the geodesic spheres with a sufficiently small radius are totally umbilical and, consequently, the given manifold has constant sectional curvature. We also furnish two other characterizations in terms of (i) an inequality involving the mean curvature of a geodesic sphere and the curvature function of their curves and (ii) the vanishing of the total torsion of closed spherical curves in the case of three-dimensional manifolds. Finally, we also show that the same results are valid for semi-Riemannian manifolds of constant sectional curvature.Comment: To appear in Annali di Matematica Pura ed Applicat

Rearrangements and radial graphs of constant mean curvature in hyperbolic space

We investigate the problem of finding smooth hypersurfaces of constant mean curvature in hyperbolic space, which can be represented as radial graphs over a subdomain of the upper hemisphere. Our approach is variational and our main results are proved via rearrangement techniques

Symmetry of global solutions to a class of fully nonlinear elliptic equations in 2D

We prove that entire bounded monotone solutions to a certain class of fully nonlinear equations in 2D are one-dimensional. Our result also gives a new (non-variational) proof of the well known De Giorgi's conjecture.Comment: 13 pages, 2 figure

Two Higgs doublet models with an S3S_3 symmetry

We study all implementations of the $S_3$ symmetry in the two Higgs doublet model with quarks, consistent with non-zero quark masses and a Cabibbo-Kobayashi-Maskawa (CKM) matrix which is not block diagonal. We study the impact of the various soft-breaking terms and vacuum expectation values, and find an interesting relation between $\alpha$ and $\beta$. We also show that, in this minimal setting, only two types of assignments are possible: either all field sectors are in singlets or all field sectors have a doublet