The Inflaton as a MSSM Higgs and Open String Modulus Monodromy Inflation

It has been recently pointed out that the polarization BICEP2 results are consistent with the identification of an inflaton mass m \simeq 10^{13} GeV with the SUSY breaking scale in an MSSM with a fine-tuned SM Higgs. This identification leads to a Higgs mass m_h \simeq 126 GeV, consistent with LHC measurements. Here we propose that this naturally suggests to identify the inflaton with the heavy MSSM Higgs system. The fact that the extrapolated Higgs coupling lambda_{SM}\simeq 0 at scales below the Planck scale suggests the Higgs degrees of freedom could be associated to a Wilson line or D-brane position modulus in string theory. The Higgs system then has a shift symmetry and an N=2 structure which guarantees that its potential has an approximate quadratic chaotic inflation form. These moduli in string compactifications, being compact, allow for a trans-Planckian inflaton field range analogous to a version of monodromy inflation.Comment: 6 pages. Misprints corrected, references adde

Minkowski 3-forms, Flux String Vacua, Axion Stability and Naturalness

We discuss the role of Minkowski 3-forms in flux string vacua. In these vacua all internal closed string fluxes are in one to one correspondence with quantized Minkowski 4-forms. By performing a dimensional reduction of the $D=10$ Type II supergravity actions we find that the 4-forms act as auxiliary fields of the Kahler and complex structure moduli in the effective action. We show that all the RR and NS axion dependence of the flux scalar potential appears through the said 4-forms. Gauge invariance of these forms then severely restricts the structure of the axion scalar potentials. Combined with duality symmetries it suggests that all perturbative corrections to the leading axion scalar potential $V_0$ should appear as an expansion in powers of $V_0$ itself. These facts could have an important effect e.g. on the inflaton models based on F-term axion monodromy. We also suggest that the involved multi-branched structure of string vacua provides for a new way to maintain interacting scalar masses stable against perturbative corrections.Comment: 39 pages. Typos corrected and added reference

Espectáculo y visualidad en la narrativa de Diamela Eltit

nota al margen del ensayo de Sergio Rojas Catástrofe y trascendencia en la narrativa de Diamela Eltit Sergio Rojas Santiago: Sangría editora, 2013

Gregorio Ossa Cerda y “Ossa y Escobar”. Un banco de avíos mineros, 1855-1884

En el presente artículo se estudia un ejemplo de las instituciones de crédito creadas a mediados del siglo XIX para el fomento de la actividad minera en la zona de Atacama. La firma “Ossa y Escobar”, creada en 1855 por el rico banquero copiapino Gregorio Ossa Cerda, se convirtió en uno de los habilitadores mas importantes de la zona de Atacama, en pleno crecimiento debido al descubrimiento de ricas minas de plata como Tres Puntas y Chimbero en la década de 1840, y posteriormente extendió sus actividades al mineral boliviano de Caracoles, descubierto en 1870. Sin embargo, la no diversificación de sus actividades, y la decadencia de las explotaciones mineras, condujo a la decadencia y liquidación final de la firma en 1884

Performance of adaptive bayesian equalizers in outdoor environments

Outdoor communications are affected by multipath propagation that imposes an upper limit on the system data rate and restricts possible applications. In order to overcome the degrading effect introduced by the channel, conventional equalizers implemented with digital filters have been traditionally used. A new approach based on neural networks is considered. In particular, the behavior of the adaptive Bayesian equalizer implemented by means of radial basis functions applied to the channel equalization of radio outdoor environments has been analyzed. The method used to train the equalizer coefficients is based on a channel response estimation. We compare the results obtained with three channel estimation methods: the least sum of square errors (LSSE) channel estimation algorithm, recursive least square (RLS) algorithm employed only to obtain one channel estimation and, finally, the RLS algorithm used to estimate the channel every decided symbol for the whole frame.Peer ReviewedPostprint (published version

Flux-induced Soft Terms on Type IIB/F-theory Matter Curves and Hypercharge Dependent Scalar Masses

Closed string fluxes induce generically SUSY-breaking soft terms on supersymmetric type IIB orientifold compactifications with D3/D7 branes. This was studied in the past by inserting those fluxes on the DBI+CS actions for adjoint D3/D7 fields, where D7-branes had no magnetic fluxes. In the present work we generalise those computations to the phenomenologically more relevant case of chiral bi-fundamental fields laying at 7-brane intersections and F-theory local matter curves. We also include the effect of 7-brane magnetic flux as well as more general closed string backgrounds, including the effect of distant (anti-)D3-branes. We discuss several applications of our results. We find that squark/slepton masses become in general flux-dependent in F-theory GUT's. Hypercharge-dependent non-universal scalar masses with a characteristic sfermion hierarchy m_E^2 < m_L^2 < m_Q^2 < m_D^2 < m_U^2 are obtained. There are also flavor-violating soft terms both for matter fields living at intersecting 7-branes or on D3-branes at singularities. They point at a very heavy sfermion spectrum to avoid FCNC constraints. We also discuss the possible microscopic description of the fine-tuning of the EW Higgs boson in compactifications with a MSSM spectrum.Comment: 67 pages, 2 figures, 2 table

Imperio, soberanía y Justicia en el pensamiento internacionalista de Francisco de Vitoria: Una re-interretación de De Indis (1532)

This article attempts to offer an alternative interpretation of Francisco de Vitoria's international thought. Much of the literature on his De Indis (1532) characterizes his view of international order as one that either opposed of justified Spanish imperialism in the New World. As against such conventional interpretations, I argue that this text is not fundamentally about the condemnation or justification of empire but, more importantly, a broad view of order that limits the exercise of state power and the recourse to war. Furthermore, it constructs a clear notion of sovereignty and international relations applicable to political communities based on an iusnaturalistic conceptualization of law and politics in the Spanish Renaissance.Este artículo ofrece una interpretación alternativa del pensamiento internacionalista de Francisco de Vitoria. Un segmento importante de la literatura en torno a De Indis (1532) caracteriza su visión del orden internacional como aquel que pudo ya sea oponerse o bien justificar el imperialismo español en el Nuevo Mundo. A diferencia de tales interpretaciones, se argumenta que dicho tracto no constituye, en lo fundamental, una condena, así como tampoco una justificación, del impulso imperial, sino una amplia visión del orden internacional que limita la conducta del poder estatal y el recurso a la guerra. Además, Vitoria ofrece una clara noción de soberanía y de las relaciones internacionales entre comunidades políticas fundamentada en una conceptualización iusnaturalista del derecho y de la política durante el renacimiento español