Neutrino mixing from the double tetrahedral group T^{\prime}

It is shown that it is possible to create successful models of flavor for both quarks and leptons using the discrete non-abelian group $T^{\prime}$ by itself. Two simple realizations are presented that can be used as the starting point for more general scenarios. In addition to the Minimal Supersymmetric Standard Model particle content, the models include three generations of right handed neutrinos and four scalar flavon fields. Three of the flavons are needed in the quark and charged lepton sector of the models and the fourth flavon participates only in the neutrino sector.Comment: 4 pages, no figures. References added and minor typos corrected. Version to appear in PR

Models of Flavor with Discrete Symmetries

In an attempt to understand the observed patterns of lepton and quark masses, models invoking a flavor symmetry $G_f$, under which the Standard Model generations are charged, have been proposed. One particularly successful symmetry, U(2), has been extensively discussed in the literature. The Yukawa matrices in models based on this symmetry reproduce the observed mass ratios in the lepton and quark sectors. The features of the symmetry that determine the texture of the Yukawa matrices can be found in other symmetries as well. We present a model based on a minimal, non-Abelian discrete symmetry that reproduces the Yukawa matrices associated with U(2) theories of flavor. In addition to reproducing the mass and mixing angle relations obtained in such theories, the different representation structure of our new horizontal symmetry allows for solutions to the solar and atmospheric neutrino problems.Comment: Prepared for the 8th Mexican Workshop on Particles and Fields, Zacatecas, Mexico; 14-20 November, 200

Why biologists should read Aristotle (or why philosophy matters for the life sciences and why the life sciences matter for philosophy)

This note discusses the importance of Natural History (biology) in the development of Aristotle philosophy and scientific outlook, and so the importance of considering Aristotle's philosophy as a necessary and useful background for contemporary biology

Synthetic life, what for and what future?

This text answers the question, posed by the editor, on the philosophical and social issues resulting from the synthetic assembly of a modified bacterial genome that was introduced in an existing bacterial species (M.mycoides)and so it was claimed to represent the first ever kind of synthetic life produced by human manipulation

On natural selection and Hume's second problem

David Hume's famous riddle of induction implies a second problem related to the question of whether the laws and principles of nature might change in the course of time. Claims have been made that modern developments in physics and astrophysics corroborate the translational invariance of the laws of physics in time. However, the appearance of a new general principle of nature, which might not be derivable from the known laws of physics, or that might actually be a non-physical one (this means completely independent of physical science) supports the notion that the course of nature can change in time. Here it is argued that natural selection satisfies the criteria that identify a general principle of nature which so far, appears to be non-derivable from the known laws of physics and therefore, it is likely that it arose in the course of time, thus leaving open again the quest for a true solution to Hume's second problem