86 research outputs found

    Chiral anomalies on a circle and their cancellation in F-theory

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    We study in detail how four-dimensional local anomalies manifest themselves when the theory is compactified on a circle. By integrating out the Kaluza-Klein modes in a way that preserves the four-dimensional symmetries in the UV, we show that the three-dimensional theory contains field-dependent Chern-Simons terms that appear at one-loop. These vanish if and only if the four-dimensional anomaly is canceled, so the anomaly is not lost upon compactification. We extend this analysis to situations where anomalies are canceled through a Green-Schwarz mechanism. We then use these results to show automatic cancellation of local anomalies in F-theory compactifications that can be obtained as a limit of M-theory on a smooth Calabi-Yau fourfold with background flux.Comment: 39 pages, 3 figures. v2: references added and typos correcte

    The Swampland Distance Conjecture for Kahler moduli

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    The Swampland Distance Conjecture suggests that an infinite tower of modes becomes exponentially light when approaching a point that is at infinite proper distance in field space. In this paper we investigate this conjecture in the K\"ahler moduli spaces of Calabi-Yau threefold compactifications and further elucidate the proposal that the infinite tower of states is generated by the discrete symmetries associated to infinite distance points. In the large volume regime the infinite tower of states is generated by the action of the local monodromy matrices and encoded by an orbit of D-brane charges. We express these monodromy matrices in terms of the triple intersection numbers to classify the infinite distance points and construct the associated infinite charge orbits that become massless. We then turn to a detailed study of charge orbits in elliptically fibered Calabi-Yau threefolds. We argue that for these geometries the modular symmetry in the moduli space can be used to transfer the large volume orbits to the small elliptic fiber regime. The resulting orbits can be used in compactifications of M-theory that are dual to F-theory compactifications including an additional circle. In particular, we show that there are always charge orbits satisfying the distance conjecture that correspond to Kaluza-Klein towers along that circle. Integrating out the KK towers yields an infinite distance in the moduli space thereby supporting the idea of emergence in that context.Comment: 47 pages, 1 figure, 4 tables. v2:minor modifications and references adde

    Cent scientifiques répliquent à SEA (Suppression des Expériences sur l’Animal vivant) et dénoncent sa désinformation

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    La lutte contre la maltraitance animale est sans conteste une cause moralement juste. Mais elle ne justifie en rien la désinformation à laquelle certaines associations qui s’en réclament ont recours pour remettre en question l’usage de l’expérimentation animale en recherche

    String Phenomenology 2019

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    The Swampland Distance Conjecture (SDC) states that an infinite tower of modes becomes exponentially light when approaching a point at infinite distance in moduli space. At the large volume singularities of the Kähler moduli spaces of Calabi-Yau threefold compactifications, we use the monodromy matrices to explicitly construct the towers of states satisfying the SDC, which consist of charge orbits of D2-D0 bound states. We further focus on the case where the CY is elliptically fibered, in which case the modular symmetry of the moduli space allows to transfer the orbits to the small fiber regime. In M-theory compactifications, which are dual to F-theory compactifications including an extra circle, some orbits always correspond to Kaluza-Klein towers along that circle. Integrating them out yields an infinite distance in the moduli space, adding support to the emergence proposal. More generally, we show that the exponential mass behavior and the infinite field distance are automatic consequences of integrating out any tower of states up to the species scale, as long as the tower gets compressed as we move in the moduli space

    6d N \mathcal{N} = (1, 0) anomalies on S1 and F-theory implications

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    On F-theory effective actions : From anomalies to Swampland

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    In this thesis we investigate general properties of four- and six-dimensional effective actions with minimal supersymmetry obtained from F-theory by compactification on Calabi-Yau manifolds. More specifically, we analyze the 4d N=1 gauge coupling functions and their one-loop corrections, we show the cancellation of chiral anomalies in four and six dimensions when the F/M-theory duality can be utilized and finally we provide yet another strong piece of evidence for the Swampland Distance Conjecture in the context of string theory, by testing it in the K\"ahler moduli spaces of Calabi-Yau threefolds. Along the way, we perform the reduction of M-theory on a Calabi-Yau fourfold in full generality, study in great detail the behaviour of anomalies under circle compactifications, settle the F-theory lift to six-dimension and provide further evidence for the relationships between the Swampland Distance Conjecture, the emergence proposal and the absence of global symmetry

    On F-theory effective actions : From anomalies to Swampland

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    In this thesis we investigate general properties of four- and six-dimensional effective actions with minimal supersymmetry obtained from F-theory by compactification on Calabi-Yau manifolds. More specifically, we analyze the 4d N=1 gauge coupling functions and their one-loop corrections, we show the cancellation of chiral anomalies in four and six dimensions when the F/M-theory duality can be utilized and finally we provide yet another strong piece of evidence for the Swampland Distance Conjecture in the context of string theory, by testing it in the K\"ahler moduli spaces of Calabi-Yau threefolds. Along the way, we perform the reduction of M-theory on a Calabi-Yau fourfold in full generality, study in great detail the behaviour of anomalies under circle compactifications, settle the F-theory lift to six-dimension and provide further evidence for the relationships between the Swampland Distance Conjecture, the emergence proposal and the absence of global symmetry

    Regional bone calcium tunover in pagetic patients treated with salmon calcitonin

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    SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe

    Mesure par une méthode originale de la fixation osseuse du calcium, totale et régionale, chez des patients pagétiques traités par la calcitonine de saumon

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    info:eu-repo/semantics/publishedGasteiner Internationales Symposion, & In Höfer, R. (1975). Radioaktive Isotope in Klinik und Forschung: Band 11. München: Urban & Schwarzenberg
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