170 research outputs found
Sustainable HEP - 2nd edition
No full textLike any field of human activity, the scientific information industry (publishers, preprint repositories, online databases, etc.) has an environmental impact that needs to be lowered as much as possible. Additionally, given the important role that the production and dissemination of scientific information play in scientific research, it can help shape community practices to become more sustainable.
Using the INSPIRE HEP information platform as a case study, I will highlight concrete challenges and potential solutions in achieving these two goals. I will also present recent initiatives to make the publishing industry more sustainable and argue that strong institutional action is crucial to achieve real change
Holographic backgrounds from D-brane probes
No full textThe gauge/string correspondence provides a non-perturbative definition of string theory and hence quantum gravity in some backgrounds, making it possible to translate statements about strongly coupled quantum field theories into results about gravity. <p><p>In this thesis, we focus on the derivation of holographic backgrounds from the field theory, without using any supergravity input. Instead, we rely crucially on the addition of probe D-branes to the stack of D-branes generating the background.<p>From the field theory description of the probe branes in the presence of the background branes, one can compute an effective action for the probes (in a suitable low-energy/near-horizon limit) by integrating out the background branes. Comparing this action with the D-brane probe action in a generic supergravity background then allows to determine the holographic background dual to the considered field theory vacuum.<p><p>In the first part, the required pre-requisites of field and string theory are recalled and this strategy to derive holographic backgrounds is explained in more detail on the basic case of D3-branes in flat space probed by a small number of D-instantons.<p><p>The second part contains the original results of this thesis, obtained by applying this strategy to several specific examples. We first derive the duals to three continuous deformations (Coulomb branch, β and non-commutative deformations) of the basic case, in the limit in which the D-instantons can probe the full geometry. We then derive the enhançon mechanism in a dual to a simple N=2 quiver gauge theory by using a fractional D-instanton as a probe and exploiting recent exact results on the Coulomb branch of N=2 quivers.<p>Finally, we obtain the near-horizon D4-brane geometry by probing the D4-branes with a small number of D0-branes.<p>Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe
The INSPIRE REST API
No full textINSPIRE is a trusted community hub that helps researchers to share and find accurate scholarly information in high energy physics. In addition to a regular web interface for interactive access to its content, a REST API is provided for programmatic access. The present document explains how to use this REST API
Gazera heliconioides subsp. micha H. Druce 1896
No full textGazera heliconioides micha (H. Druce, 1896) (Fig. 13) Castnia micha (H. Druce, 1896) Taxonomic history. Described in the genus Castnia by Druce (1896) but later included in the genus Cabirus by Houlbert (1918). Talbot (1919) mentions that micha “can only be considered as a race and not as a distinct species”. Distribution. This subspecies is known from Bolivia, Paraguay and South East Brazil (Miller 1986; Lamas 1995; Rothschild 1919). Jörgensen (1930) states that it is common in all the Eastern region of Paraguay. It is, apparently, together with Castnia invaria penelope, the commonest castniid species in Paraguay. Jörgensen (1930) mentions that it flies in forested areas, near bromeliads (Bromelia sp. and Ananas sp.). It is frequently found perching close to the ground at the base of leaves or grasses and the way the moth rests and its wing and body coloration (Fig. 20 b) allows it to “disappear” in the surroundings. The first author observed individuals flying in urban places of Asunción, the capital city of Paraguay. He also observed them flying in Sapucay, Paraguarí Department and in Cerro Corá, Amambay Department. Ulf Drechsel (pers. comm.) collected and observed specimens in Sapucay, Paraguarí Department, and in Areguá, Central Department; while Contreras (2009) collected them in Ñeembucú Department. Biology and behavior. Like all taxa in the genus, they have a close resemblance to members of Lycorea Doubleday (Nymphalidae: Danainae), Thyridia Hübner and Methona Doubleday (Nymphalidae: Danainae, Ithomiini), and to Notophyson heliconides (Swainson) (Erebidae: Arctiinae, Pericopini) (Miller 1986; Lamas 1973). Two males were observed by the first author in Paraguarí and Amambay Departments, while flying low and slowly, along paths surrounded with Bromelia balansae Mez, which allowed for easy collection. They also perched close to the ground (Fig. 21). These observations clearly contrast with those made by Contreras (2009) in more disturbed habitats, where specimens were found flying fast, strongly and very high (7–8 m above ground).The host plant is unknown, but we suspect that the larvae feed on Bromelia spp. and/or Ananas spp. Contreras (2009) mentions that Orchidaceae could also be hosts of this species. Material examined. 13, Castnia micha Druce, 494, Paraguay (SMNH). CORDILLERA: Caacupé, 22.IX. 1969 (FCA/ DE); 1 Ƥ, Atyrá, X. 2002, Coll. C.Aguilar (MNHNPY). GUAIRÁ: 233,1 Ƥ, “ Paraguay, Independencia”, A. Breyer Collection (MLP); 13, 1 Ƥ, Carlos Pfannl, Paraguay, no date (TPC). CAAGUAZÚ: Coronel Oviedo, 25.X. 1972 (FCA/ DE); 13, “ Paraguay, Caa-Guazú”, XII- 1948, Coll. F.H. Schade, A. Breyer Collection (MLP);. PARAGUARÍ: 13, Sapucay. 8. X. 2008. Coll. S.Ríos (MNHNPY); 13, Sapucay, Paraguay 8.XI. 1997. Coll. U. Drechsel (MNHNPY); 13, Sapucay, Oct. 24, [1] 900 (NHMUM). CENTRAL: San Lorenzo, 23.X. 1985 Coll. J.Estigarribia (FCA/ DE). ÑEEMBUCÚ: 13, Distrito Humaitá, Arroyo Franco Cué, 15.XI. 2006 (IBIS, 1719) (IBIS-UNP); 13, Distrito Isla Umbú, Arroyo Hondo, paraje Itá Cajón, 13.XII. 2006 (IBIS, 2109) (IBIS-UNP). AMAMBAY: 13, Parque Nacional Cerro Corá, 25.X. 2009 Coll. S.Ríos (MNHNPY).Published as part of Ríos, Sergio D. & González, Jorge M., 2011, A synopsis of the Castniidae (Lepidoptera) of Paraguay, pp. 43-61 in Zootaxa 3055 on pages 53-54, DOI: 10.5281/zenodo.27891
Chiral observables and S-duality in N = 2⋆ U(N ) gauge theories
No full textWe study N=2* theories with gauge group U(N ) and use equivariant localization to calculate the quantum expectation values of the simplest chiral ring elements. These are expressed as an expansion in the mass of the adjoint hypermultiplet, with coefficients given by quasi-modular forms of the S-duality group. Under the action of this group, we construct combinations of chiral ring elements that transform as modular forms of definite weight. As an independent check, we confirm these results by comparing the spectral curves of the associated Hitchin system and the elliptic Calogero-Moser system. We also propose an exact and compact expression for the 1-instanton contribution to the expectation value of the chiral ring elements
D-instanton probe and the enhancon mechanism from a quiver gauge theory
No full textWe study the N = 2 field theory realized by D3-branes on the C2/Z2 orbifold. The dual supergravity solution exhibits a repulson singularity cured by the enhancon mechanism. By comparing the open and closed string descriptions of a probe D-instanton, we can compute the exact non-perturbative profile of the supergravity twisted field, which determines the supergravity background. We then show how the non-trivial IR physics of the field theory translates into the stringy effects that give rise to the enhancon mechanism and the associated excision procedure. © The Authors.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Emergent D4-brane background from D-particles
No full textWe show that the solution of a pre-geometric strongly coupled quantum mechanical model describing K D-particles in the presence of N D4-branes in type IIA string theory, at fixed K and large N, yields an effective action describing the motion of the K D-particles in a classical ten-dimensional curved spacetime. By comparing the effective action with the non-abelian D-brane action in an arbitrary supergravity background, we identify the metric, dilaton and Ramond-Ramond fields and find a precise match with the near-horizon D4-brane geometry.info:eu-repo/semantics/publishe
Micha Ullman: specific and general
No full textTento text si klade za cíl předvést důležitou edukační interpretační praxi,která souvisí s analýzou edukovaného díla, totiž s budováním zdůvodněnéhokontextu pro vybranou strategii. V první části textu Micha Ullman: sochyna rozhraní nebe – země prozkoumáme dílo autora, který začal tvořit v se-dmdesátých letech a jeho tvorba je kontinuálně vystavována.V druhé části Strategie a její variace: nalezení shodného při vědomí odliš-ností teoreticky zakotvíme odlišnost mezi konkrétní praxí autora a strategiíjako objevenou obecninou. Objevovat strategie, umět je chápat ve spojitostis určitou dobou, znamená, že při významných shodách zároveň zazname-náváme odlišnosti a vsazujeme jev do adekvátního kontextu. Je to jednakvelmi účinná edukativní možnost, jak chápat dějiny oboru v souvislostecha trsech a neutápět se v jednotlivých případech autorských řešení, ale takémožnost, jak pro jednotlivé autory získat výkladový rámec porovnáváníma vyhledáváním shod při podstatných odlišnostech s jinými.This text aims to demonstrate an important educational interpretation prac-tice that is related to the analysis of the educated work, namely to buildinga justified context for the chosen strategy. In the first part of the text MichaUllman: sculptures at the interface of heaven and earth, we will explore thework of the author, who started creating in the seventies and whose workis continuously exhibited.In the second part, Strategy and its variations: finding the same whilebeing aware of differences, we theoretically anchor the difference betweenthe specific practice of the author and strategy as a discovered generality.Discovering strategies, being able to understand them in connection witha certain time, means that in case of significant similarities, we simultaneou-sly note differences and place the phenomenon in an adequate context. It is,on the one hand, a very effective educational opportunity to understand thehistory of the field in contexts and clusters and not to get bogged down inindividual cases of authorial solutions, but also an opportunity to obtain aninterpretive framework for individual authors by comparing and searchingfor similarities in substantial differences with others
Instanton corrections for m and Ω
No full textIn this paper, we study instanton corrections in the N=2⋆ gauge theory by using its description in string theory as a freely-acting orbifold. The latter is used to compute, using the worldsheet, the deformation of the Yang–Mills action. In addition, we calculate the deformed instanton partition function, thus extending the results to the non-perturbative sector of the gauge theory. As we point out, the structure of the deformation is extremely similar to the Ω-deformation, therefore confirming the universality of the construction. Finally, we comment on the realisation of the mass deformation using physical vertex operators by exploiting the equivalence between Scherk–Schwarz deformations and freely-acting orbifolds
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