204,461 research outputs found
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
Reclaiming Our Subjugated Truths—Using Hip Hop as a Form of Decolonizing Public Pedagogy: The Case of Didier Awadi
This paper explores how Senegalese Hip Hop pioneer, Didier Awadi, uses Hip Hop as a form of decolonizing public pedagogy that renders the contributions of Pan-African leaders visible to Africa and the world, contributions that are often omitted and vilified by mainstream history. I argue that Awadi’s work provides a strategy for reclaiming oral literature, particularly storytelling, as a legitimate way of knowing, teaching and learning history. In his album Présidents d’Afrique, Didier Awadi uses rap and traditional African music to retell the story of our resistant past through an African frame of reference. The data is comprised of (1) a one-on-one interview with Didier Awadi and (2) one song of Présidents d’Afrique that best exemplifies how his storytelling narrates notions of African histories often erased in Eurocentric history. The data is analyzed using Ruth Reviere’s five Afrocentric research criteria: “ukweli (truth), ujamaa (community), kujitoa (commitment), uhaki (justice), and utulivu (harmony)” to determine whether Didier Awadi’s stories are grounded in African knowledge
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
- …