First order signatures in 4D pure compact U(1) gauge theory with toroidal and spherical topologies

We study the pure compact U(1) gauge theory with the extended Wilson action (\beta, \gamma couplings) by finite size scaling techniques, in lattices ranging from L=6 to L=24 in the region of \gamma <= 0 with toroidal and spherical topologies. The phase transition presents a double peak structure which survives in the thermodynamical limit in the torus. In the sphere the evidence support the idea of a weaker, but still first order, phase transition. For negative values of gamma the transition becomes weaker and larger lattices are needed to find its asymptotic behaviour. Along the transient region the behaviour is the typical one of a weak first order transition for both topologies, with a region where 1/d < nu < 0.5, which becomes nu compatible with 1/d when larger lattices are used.Comment: Some references added; changes in the text mainly wording. To appear in Phys. Lett.

Towards a new quantization of Dirac's monopole

There are several mathematical and physical reasons why Dirac's quantization must hold. How far one can go without it remains an open problem. The present work outlines a few steps in this direction.Comment: To appear in Proceedings of "IV Taller de la Division de Gravitacion y Fisica Matematica". Misprints corrected, references and acknowledgments adde

Improved tangent-cone method for the Aerodynamic Preliminary Analysis System (APAS) version of the hypersonic arbitrary-body program

The Aerodynamic Preliminary Analysis System (APAS) utilizes a modified version of the Hypersonic Arbitrary-Body Program (HABP) Mark 3 code in its analysis rationale. Four methods are considered for incorporation into the code as the tangent-cone method. The combination of second-order slender body theory and the approximate solution of Hammitt and Murthy shows the best agreement with the exact numerical solutions and is thus included in the APAS production version of the HABP code

On representations of the rotation group and magnetic monopoles

Recently (Phys. Lett. A302 (2002) 253, hep-th/0208210; hep-th/0403146) employing bounded infinite-dimensional representations of the rotation group we have argued that one can obtain the consistent monopole theory with generalized Dirac quantization condition, $2\kappa\mu \in \mathbb Z$, where $\kappa$ is the weight of the Dirac string. Here we extend this proof to the unbounded infinite-dimensional representations.Comment: References adde

Low speed reentry guidance dispersion evaluation

Mathematical models for low speed reentry guidance of Apollo vehicle

Using Formative Research and Audience-Centric Intelligence to Develop the #JustBe Digital Magazine: An mHealth Strategy to Improve Adolescent Sexual Health

Digital strategies may help to overcome challenges in providing contraception education to overlooked and key sub-populations (older teens, ethnic minority youth, LGBTQ youth, high school dropouts and males). However, many current digital strategies are not culturally specific and often have limited information on the most effective contraceptive methods. In this article, we describe the preliminary steps used to develop #JustBe, a user-centered digital strategy for ethnic minority older youth and young adults with a specific focus contraception, sexual health, consent, and healthy relationships. Technology-based strategies such as #JustBe offer advantages over traditional face-to-face methods by utilizing a confidential way to retrieve sexual health information that may be sensitive and potentially embarrassing. Questions still remain regarding the feasibility and long-term effects of mobile health interventions for contraception use