1,953 research outputs found
Boundary Conformal Anomalies on Hyperbolic Spaces and Euclidean Balls
We compute conformal anomalies for conformal field theories with free
conformal scalars and massless spin fields in hyperbolic space
and in the ball , for . These
spaces are related by a conformal transformation. In even dimensional spaces,
the conformal anomalies on and are shown to
be identical. In odd dimensional spaces, the conformal anomaly on
comes from a boundary contribution, which exactly coincides
with that of provided one identifies the UV short-distance
cutoff on with the inverse large distance IR cutoff on
, just as prescribed by the conformal map. As an
application, we determine, for the first time, the conformal anomaly
coefficients multiplying the Euler characteristic of the boundary for scalars
and half-spin fields with various boundary conditions in and .Comment: 16 pages. V3: small correction
Operator Mixing in Large Superconformal Field Theories on and Correlators with Wilson loops
We find a general formula for the operator mixing on the of
chiral primary operators (CPO) for the theory at large in
terms of Chebyshev polynomials. As an application, we compute the correlator of
a CPO and a Wilson loop, reproducing an earlier result by Giombi and Pestun
obtained from a two-matrix model proposal. Finally, we discuss a simple method
to obtain correlators in general superconformal field theories in
perturbation theory in terms of correlators of the theory.Comment: 15 pages, no figure
A limit for large -charge correlators in theories
Using supersymmetric localization, we study the sector of chiral primary
operators with large -charge in
four-dimensional superconformal theories in the weak coupling
regime , where is kept fixed as
, representing the gauge theory coupling(s). In this limit,
correlation functions of these operators behave in a simple way, with
an asymptotic behavior of the form , modulo
corrections, with for a gauge
algebra and a universal function . As a
by-product we find several new formulas both for the partition function as well
as for perturbative correlators in gauge theory
with fundamental hypermultiplets
Cross sections for production of closed superstrings at high energy colliders in brane world models
In brane world string models with large extra dimensions, there are processes
where fermion and antifermion (or two gluons) can annihilate producing a light
particle (e.g. gluon) carrying transverse momentum and a Kaluza-Klein graviton
or an excited closed string that propagates in the extra dimensions. In high
energy colliders, this process gives a missing momentum signature. We compute
the total cross section for this process within the context of type II
superstring theory in the presence of a D brane. This includes all missing
energy sources for this string theory model up to s=8M_s^2, and it can be used
to put new limits on the string scale M_s.Comment: 18 pages, 3 figures. Reference adde
Il Sistema di Gestione di un Laboratorio di Ricerca & Sviluppo - il caso Compolab
In questa tesi viene descritto il lavoro svolto durante l’attività di tirocinio presso il laboratorio COMPOLAB, azienda che si occupa di validazione virtuale ed innovazione di prodotto e processi industriali. L’elaborato inizia con una breve descrizione dell’azienda. Vengono poi illustrati il sistema di gestione delle informazioni, il sistema di gestione dei progetti, il sistema di rilevazione del lavoro svolto in azienda, il foglio di lavoro per il bilancio di progetto e il piano della qualità del laboratorio. Per ogni elemento vengono chiarite le problematiche iniziali e le esigenze dell’azienda, per proseguire con la descrizione della metodologia di lavoro, delle soluzioni adottate e dei risultati ottenuti. Infine vengono tratte le conclusioni sull’impatto che il lavoro svolto ha avuto sull’azienda e gli sviluppi futuri previsti per il sistema di gestione
Characterization of long period gratings manufactured with fiber optic fusion splicer for sensor development
A Long Period Grating (LPG) is a structure inscribed in an optical fiber that is of great interest in the field of communications and sensors. At Centro de Investigaciones Ópticas (CIOp), an LPG manufacturing process was implemented. It is based on use of electric arcs produced with an optical fiber splicer to generate a series of physical disturbances that modify optical fiber behavior as a light transmission guide. Since transmission response of LPG is sensitive to fiber environment conditions, it can be used to detect changes in certain physical and chemical parameters. In particular, it enables the implementation of optical sensors sensitive to temperature, surrounding medium refractive index and axial deformation. Characterization of locally generated LPGs is essential for future design of sensors applicable in many engineering areas. In this article, typical LPG sensitivities to the three mentioned parameters are reportedFil: Alustiza, Diego Horacio. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; Argentina. Universidad Tecnológica Nacional. Facultad Regional La Plata. Departamento de Ciencias Básicas; ArgentinaFil: Mineo, Marcos. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Russo, Nelida Araceli. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones CientÃficas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; Argentin
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