Supersymmetric exact sequence, heat kernel and super KdV hierarchy

We introduce the free N=1 supersymmetric derivation ring and prove the existence of an exact sequence of supersymmetric rings and linear transformations. We apply necessary and sufficient conditions arising from this exact supersymmetric sequence to obtain the essential relations between conserved quantities, gradients and the N=1 super KdV hierarchy. We combine this algebraic approach with an analytic analysis of the super heat operator.We obtain the explicit expression for the Green's function of the super heat operator in terms of a series expansion and discuss its properties. The expansion is convergent under the assumption of bounded bosonic and fermionic potentials. We show that the asymptotic expansion when $t\to0^+$ of the Green's function for the super heat operator evaluated over its diagonal generates all the members of the N=1 super KdV hierarchy.Comment: 20 pages, to be published in JM

Bounds on masses of bulk fields in string compactifications

In string compactification on a manifold X, in addition to the string scale and the normal scales of low-energy particle physics, there is a Kaluza-Klein scale 1/R associated with the size of X. We present an argument that generic string models with low-energy supersymmetry have, after moduli stabilization, bulk fields with masses which are parametrically lighter than 1/R. We discuss the implications of these light states for anomaly mediation and gaugino mediation scenarios.Comment: 15 page

The deterioration of Circular Mausoleum, Roman Necropolis of Carmona, Spain

The Circular Mausoleum tomb in the Roman Necropolis of Carmona was carved on a calcarenite sequence in an ancient quarry located in the town of Carmona, Southern Spain. This rock-cut tomb, representative of Roman burial practices, currently suffers from serious deterioration. A detailed survey over several years permitted the identification of the main tomb's pathologies and damaging processes, which include loss of material (scaling, flaking, granular disintegration), surface modifications (efflorescences, crusts and deposits) and extensive biological colonization. The results obtained in this study indicated that anthropogenic changes were largely responsible and enhanced the main alteration mechanisms observed in the Circular Mausoleum. Based on the deterioration diagnosis, effective corrective actions were proposed. This study shows that any conservative intervention in the interior of the tomb should be preceded by accurate in situ measurements and laboratory analyses to ascribe the source of the deterioration damages and thus designing effective treatments.This research was funded by the Consejeria de Cultura, Junta de Andalucia, the Spanish Ministry of Science and Innovation project CGL2010-17183, and the program Torres Quevedo (PTQ 13-06296 and PTQ 12-05601)

Astrophysical and Cosmological Implications of Large Volume String Compactifications

We study the spectrum, couplings and cosmological and astrophysical implications of the moduli fields for the class of Calabi-Yau IIB string compactifications for which moduli stabilisation leads to an exponentially large volume V ~ 10^{15} l_s^6 and an intermediate string scale m_s ~ 10^{11}GeV, with TeV-scale observable supersymmetry breaking. All K\"ahler moduli except for the overall volume are heavier than the susy breaking scale, with m ~ ln(M_P/m_{3/2}) m_{3/2} ~ (\ln(M_P/m_{3/2}))^2 m_{susy} ~ 500 TeV and, contrary to standard expectations, have matter couplings suppressed only by the string scale rather than the Planck scale. These decay to matter early in the history of the universe, with a reheat temperature T ~ 10^7 GeV, and are free from the cosmological moduli problem (CMP). The heavy moduli have a branching ratio to gravitino pairs of 10^{-30} and do not suffer from the gravitino overproduction problem. The overall volume modulus is a distinctive feature of these models and is an M_{planck}-coupled scalar of mass m ~ 1 MeV and subject to the CMP. A period of thermal inflation can help relax this problem. This field has a lifetime ~ 10^{24}s and can contribute to dark matter. It may be detected through its decays to 2\gamma or e^+e^-. If accessible the e^+e^- decay mode dominates, with Br(\chi \to 2 \gamma) suppressed by a factor (ln(M_P/m_{3/2}))^2. We consider the potential for detection of this field through different astrophysical sources and find that the observed gamma-ray background constrains \Omega_{\chi} <~ 10^{-4}. The decays of this field may generate the 511 keV emission line from the galactic centre observed by INTEGRAL/SPI.Comment: 31 pages, 2 figures; v2. refs adde

Magnetic Raman Scattering in Two-Dimensional Spin-1/2 Heisenberg Antiferromagnets: Spectral Shape Anomaly and Magnetostrictive Effects

We calculate the Raman spectrum of the two-dimensional (2D) spin-1/2 Heisenberg antiferromagnet by exact diagonalization and quantum Monte Carlo techniques on clusters of up to 144 sites and, on a 16-site cluster, by considering the phonon-magnon interaction which leads to random fluctuations of the exchange integral. Results are in good agreement with experiments on various high-T_c precursors, such as La_2CuO_4 and YBa_2Cu_3O_{6.2}. In particular, our calculations reproduce the broad lineshape of the two-magnon peak, the asymmetry about its maximum, the existence of spectral weight at high energies, and the observation of nominally forbidden A_{1g} scattering.Comment: 12 pages, REVTEX, 1 postscript figur

A Simplest A4 Model for Tri-Bimaximal Neutrino Mixing

We present a see-saw $A_4$ model for Tri-Bimaximal mixing which is based on a very economical flavour symmetry and field content and still possesses all the good features of $A_4$ models. In particular the charged lepton mass hierarchies are determined by the $A_4\times Z_4$ flavour symmetry itself without invoking a Froggatt-Nielsen U(1) symmetry. Tri-Bimaximal mixing is exact in leading order while all the mixing angles receive corrections of the same order in next-to-the-leading approximation. As a consequence the predicted value of $\theta_{13}$ is within the sensitivity of the experiments which will take data in the near future. The light neutrino spectrum, typical of $A_4$ see-saw models, with its phenomenological implications, also including leptoproduction, is studied in detail.Comment: 20 pages, 2 figure

Mixed Mediation of Supersymmetry Breaking with Anomalous U(1) Gauge Symmetry

Models with anomalous U(1) gauge symmetry contain various superfields which can have nonzero supersymmetry breaking auxiliary components providing the origin of soft terms in the visible sector, e.g. the U(1) vector superfield, the modulus or dilaton superfield implementing the Green-Schwarz anomaly cancellation mechanism, U(1)-charged but standard model singlet matter superfield required to cancel the Fayet-Iliopoulos term, and finally the supergravity multiplet. We examine the relative strength between these supersymmetry breaking components in a simple class of models, and find that various different mixed mediations of supersymmetry breaking, involving the modulus, gauge, anomaly and D-term mediations, can be realized depending upon the characteristics of D-flat directions and how those D-flat directions are stabilized with a vanishing cosmological constant. We identify two parameters which represent such properties and thus characterize how the various mediations are mixed. We also discuss the moduli stabilization and soft terms in a variant of KKLT scenario, in which the visible sector K\"ahler modulus is stabilized by the D-term potential of anomalous U(1) gauge symmetry.Comment: 30 pages, 5 figure

Radon (222Rn) outgassing in San Juan volcanic tubes during the Cumbre Vieja eruption 2021, and preliminary values in the new volcanic tubes

Comunicación oral presentada en el 1st European Meeting on Geomicrobiology of volcanic caves. días 2-3 de marzo de 2023 celebrado en la Casa de la Ciencia-CSIC de SevillaDuring the eruption at Cumbre Vieja ridge (La Palma, Canary Islands, 2021) a radon (222Rn) detector (CORENTIUM Pro alpha particles counter) was emplaced inside the “Las Palomas” lava tube (San Juan eruption, 1949). In addition, a CO2 meter logger was emplaced to determine relationships between the 2021 eruption and radon plus CO2 inner fluxes. There is a geostructural relationship between the 1949 and 2021 eruptions, probably connected by a previous fault, shown the volcanic vents’ alignment trending NW-SE. In October 2021, the radon and CO2 loggers were moved to the upper part of the lava tube, in the San Juan volcanic vent (Llano del Banco hollow dyke). Once the eruption ended (in early 2022) both loggers were placed in one newly formed lava tube, and data will be collected in February 2023. Preliminary results show daily average radon values ranging between 2 - 9 Bq/m3, although sporadic peaks of about 270 and 650 Bq/m3 were recorded related to volcano-tectonic earthquakes and volcanic intensity. In general, basaltic eruptions of alkaline affinity show low radon values due to the low concentration in the magma body of uranium and related chemical elements (Th, Ra, etc.). Geochemical analysis of emitted lavas shows a U concentration of about 1 to 5 ppm (μg/g) and Th 9.5 ppm. Summer values of Rn increased up to 3 KBq/m3, related to the climate conditions instead of volcanic activity.This study was funded by the project CSIC 20223PAL002 “Investigación Geológica de la Erupción de 2021 en Cumbre Vieja” and partially by the project FAMRAD (PID2020-113407RB-I00): Geochemical modeling of seismic prediction from endogenous gas emission (222Rn, CO2, CH4), and earthquakes by using radioactive caves and boreholes in the Alhama de Murcia fault.N

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death

Influencia del oxígeno a alta concentración en cámara hiperbárica sobre el metabolismo óseo

RESUMEN: Objetivos: Conocer las acciones del oxígeno a alta concentración en cámara hiperbárica (CH) sobre la expresión de genes relacionados con el metabolismo óseo en líneas celulares osteoblasticas y hueso trabecular humano. Material y métodos: Se analizó la expresión diferencial de varios genes relacionados con el metabolismo óseo (SOST, RUNX2, MMP14, OPG, HIF‐1α y SIRT1) en dos líneas celulares osteoblasticas humanas (Saos y Super‐Saos) y en fragmentos de hueso trabecular humano sometidos a una, tres o cinco sesiones de CH (90 minutos, oxigeno 100%; 2,3 atmosferas). En cada experimento se utilizó un control que no recibió CH. Resultados: No encontramos diferencias significativas tras la CH en la expresión de los genes estudiados, ni en las células ni en hueso trabecular. Solo en la línea celular Super‐Saos la expresión de OPG tras 5 sesiones de CH descendió 6 veces con respecto a la del grupo control (2‐ΔCt de 72; p=0,01). Conclusiones: El oxígeno a alta concentración en cámara hiperbárica no parece tener influencia en la expresión de genes relacionados con el metabolismo óseo