102,223 research outputs found
Supersymmetric Born-Infeld actions and new Fayet-Iliopoulos terms
No full text© 2019, The Author(s). We consider N = 1 supersymmetric Born-Infeld actions that have a second non-linear supersymmetry. We focus on the model proposed by Bagger and Galperin and show that the breaking of the second supersymmetry is sourced by the new Fayet-Iliopoulos D-term. Interpreting such an action as the effective theory of a space-filling (anti) D3-brane leads to an expression for the new Fayet-Iliopoulos parameter in terms of the brane tension and α′.sponsorship: We thank Stefanos Katmadas, Alex Kehagias, Antoine Van Proeyen and Timm Wrase for discussions. The work of N.C. is supported by an FWF grant with the number P 30265. The work of F.F. is supported from the KU Leuven C1 grant ZKD1118 C16/16/005. The work of M.T. is supported by the FWO Odysseus Grant No. G.0.E52.14N. (FWF grant|P 30265, KU Leuven C1 grant|ZKD1118 C16/16/005, FWO Odysseus Grant|G.0.E52.14N)status: Publishe
Worldlines on Orbifolds and the Fayet-Iliopoulos Term
No full textWe adapt ``string-inspired'' worldline techniques to one-loop calculations on orbifolds, in particular on the orbifold. Our method also allows for the treatment of brane-localized terms, or bulk-brane couplings. For demonstration, we reproduce the well-known result for the one-loop induced Fayet-Iliopoulos term in rigidly supersymmetric Abelian gauge theory, and generalize it to the case where soft supersymmetry breaking mass terms for the bulk scalar fields are present on the branes.We adapt ``string-inspired'' worldline techniques to one-loop calculations on orbifolds, in particular on the orbifold. Our method also allows for the treatment of brane-localized terms, or bulk-brane couplings. For demonstration, we reproduce the well-known result for the one-loop induced Fayet-Iliopoulos term in rigidly supersymmetric Abelian gauge theory, and generalize it to the case where soft supersymmetry breaking mass terms for the bulk scalar fields are present on the branes
Fayet–Iliopoulos D-term in non-supersymmetric heterotic string orbifolds
No full textThe Fayet–Iliopoulos D-term is a common feature in string vacua that contain an anomalous U(1) gauge symmetry, and arises from a one-loop diagram in string perturbation theory. The same diagram is generated in string vacua in which supersymmetry is broken directly at the string scale, either via spontaneous Scherk–Schwarz breaking, in which case the gravitino mass is determined by the radius of the circle used in the Scherk–Schwarz mechanism, or via explicit supersymmetry breaking by the GSO projections. We analyse the resulting would-be Fayet–Illiopoulos D-term in the non-supersymmetric string vacua and its contribution to the vacuum energy. A numerical estimate in an explicit tachyon-free string-derived model suggests that the would-be D-term contribution may uplift the vacuum energy to a positive value.The Fayet-Iliopoulos -term is a common feature in string vacua that contain an anomalous gauge symmetry, and arises from a one--loop diagram in string perturbation theory. The same diagram is generated in string vacua in which supersymmetry is broken directly at the string scale, either via spontaneous Scherk-Schwarz breaking, in which case the gravitino mass is determined by the radius of the circle used in the Scherk-Schwarz mechanism, or via explicit supersymmetry breaking by the GSO projections. We analyse the resulting would-be Fayet-Illiopoulos -term in the non-supersymmetric string vacua and its contribution to the vacuum energy. A numerical estimate in an explicit tachyon-free string-derived model suggests that the would-be -term contribution may uplift the vacuum energy to a positive value
Le spectacle de la Révolution. La culture visuelle des commémorations d’Octobre, sous la dir. de G. Haver, J.F. Fayet, V. Gorin et E. Koustova, Lausanne 2017
No full textAutant-Mathieu Marie-Christine. Le spectacle de la Révolution. La culture visuelle des commémorations d’Octobre, sous la dir. de G. Haver, J.F. Fayet, V. Gorin et E. Koustova, Lausanne 2017. In: Revue Russe n°50, 2018. Miscélanées. La Russie de 1869 à nos jours... pp. 246-247
Fayet-Iliopoulos D-Term in Non-Supersymmetric Heterotic String Orbifolds
No full textThe Fayet-Iliopoulos -term is a common feature in string
vacua that contain an anomalous gauge symmetry, and arises from a
one--loop diagram in string perturbation theory. The same diagram is generated
in string vacua in which supersymmetry is broken directly at the string scale,
either via spontaneous Scherk-Schwarz breaking, in which case the gravitino
mass is determined by the radius of the circle used in the Scherk-Schwarz
mechanism, or via explicit supersymmetry breaking by the GSO projections. We
analyse the resulting would-be Fayet-Illiopoulos -term in the
non-supersymmetric string vacua and its contribution to the vacuum energy. A
numerical estimate in an explicit tachyon-free string-derived model suggests
that the would-be -term contribution may uplift the vacuum energy to a
positive value.Comment: 11 pages, 1 figur
(BPS) Fayet-Iliopoulos Terms in 5D Orbifold SUGRA
No full textWe discuss Fayet-Iliopoulos terms in the context of five-dimensional supergravity compactified on an orbifold. For this purpose we use our superfield formulation of the off-shell 5D SUGRA. In the case of tuned FI terms, contrary to other claims, we find BPS solutions which ensure that N=1 supersymmetry is unbroken also in warped geometries. As in the rigid case, the FI terms induce odd masses for charged hypermultiplets, leading to the (de)localisation of the KK wave-functions near the fix-point branes. In the case of ungauged U(1)_R symmetry, we present also supersymmetric warped solutions in the presence of non-trivial profiles of charged hyperscalars.We discuss Fayet-Iliopoulos terms in the context of five-dimensional supergravity compactified on an orbifold. For this purpose we use our superfield formulation of the off-shell 5D SUGRA. In the case of tuned FI terms, contrary to other claims, we find BPS solutions which ensure that N=1 supersymmetry is unbroken also in warped geometries. As in the rigid case, the FI terms induce odd masses for charged hypermultiplets, leading to the (de)localisation of the KK wave-functions near the fix-point branes. In the case of ungauged U(1)_R symmetry, we present also supersymmetric warped solutions in the presence of non-trivial profiles of charged hyperscalars.We discuss Fayet–Iliopoulos terms in the context of five-dimensional supergravity compactified on an orbifold. For this purpose we use our superfield formulation of the off-shell 5D SUGRA. In the case of tuned FI terms, contrary to other claims, we find BPS solutions which ensure that N=1 supersymmetry is unbroken also in warped geometries. As in the rigid case, the FI terms induce odd masses for charged hypermultiplets, leading to the (de)localisation of the KK wave-functions near the fix-point branes. In the case of ungauged U(1)R symmetry, we present also supersymmetric warped solutions in the presence of non-trivial profiles of charged hyperscalars
On Fayet-Iliopoulos terms and de Sitter vacua in supergravity: some easy pieces
No full textWe clarify a number of issues on Fayet-Iliopoulos (FI) terms in supergravity, keeping the formalism at a minumum and making use of explicit examples. We explain why, if the U(1) vector is massive everywhere in field space, FI terms are not genuine and can always be redefined away or introduced when they are not present. We formulate a simple anomaly-free model with a genuine FI term, a classically stable de Sitter (dS) vacuum and no global symmetries. We explore the relation between N = 2 and N = 1 FI terms by discussing N = 1 truncations of N = 2 models with classically stable dS vacua
Vaccination du cheval contre la grippe équine à l’aide d’un vaccin inactivé polyvalent
No full textCottereau Ph., Petermann H. G., Fayet M. T., Papageorgiou C., Valette L., Vicaria J. M. Vaccination du cheval contre la grippe équine à l’aide d’un vaccin inactivé polyvalent. In: Bulletin de l'Académie Vétérinaire de France tome 122 n°4, 1969. pp. 141-146
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