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| Campo DC | Valor | Lengua/Idioma |
|---|---|---|
| dc.provenance | Facultad de Ciencias Exactas y Naturales de la UBA | - |
| dc.contributor | Chimento, Luis P. | - |
| dc.contributor | Forte, Mónica | - |
| dc.creator | Forte, Mónica | - |
| dc.date.accessioned | 2018-05-04T22:07:33Z | - |
| dc.date.accessioned | 2018-05-28T16:48:27Z | - |
| dc.date.available | 2018-05-04T22:07:33Z | - |
| dc.date.available | 2018-05-28T16:48:27Z | - |
| dc.date.issued | 2011 | - |
| dc.identifier.uri | http://10.0.0.11:8080/jspui/handle/bnmm/74597 | - |
| dc.description | Estudiamos escenarios de expansión acelerada en cosmologías de Bianchi I(BI) y Friedmann-Robertson-Walker (FRW) con distintos componentes. En la métrica de BI encontramos modelos de universos con K esencia que disipaban la anisotropía primordial y modelos que eludían la singularidad inicial. Encontramos soluciones exactas para diversas fuentes y vimos que la K esencia impulsada por un potencial cuadrá́tico inverso y la quintaesencia impulsada por un potencial exponencial compartían la misma geometría. En la métrica de FRW, la K esencia permitió construir modelos que interpolaban entre una era dominada por materia oscura, y una era de expansión acelerada. Introdujimos el N-quintom que generalizaba el quintom construido con quintaesencia y campo fantasma. Estudiamos la dualidad, la estabilidad de las soluciones ley de potencias y obtuvimos la solución general del N-quintom impulsado por un potencial exponencial. Para otros potenciales investigamos modelos en espacios internos bi y tridimensionales. Asociamos una representación escalar a un sistema de dos fluidos interactivos que modificó la ecuación de Friedmann, denominada “quintaesencia exótica”. Ajustamos estadísticamente los par ́metros del modelo exótico, estimamos cuando el universo comenzaba a acelerarse, calculamos su edad, estudiamos las perturbaciones lineales y encontramos la solución general con tres fluidos. Finalmente, analizamos modelos con materia barió́nica conservada y con interacciones del sector oscuro limitadas a cocientes asintóticamente estables de las densidades de energía oscuras. | - |
| dc.description | In this thesis we study cosmological scenarios in the metrics of Bianchi I (BI) and Friedmann-Robertson-Walker (FRW) with different contents. In the BI metric we investigate a universe with K essence and find some models that dissipate the primary anisotropy and others that avoid the initial singularity. We find exact solutions with various sources and find that the K essence driven by an inverse square potential and a quintessence driven by exponential potential share the same geometry. In the FRW metric we see that the K essence allows us to build transient models representing universes that interpolate between a non-accelerated expansion era dominated by dark matter, and a stage of accelerated expansion, dominated by dark energy. Alternatively, we introduce the N-quintom model with an internal structure that generalizes different realizations of quintom based on quintessence and ghost fields. We study the duality and show that the power-law type solutions are stable when the N-quintom is driven by an exponential potential, for which we obtain the general solution. Also, we consider models with other potentials and solve for the two and three-dimensional internal spaces. We present the problem of interacting fluids and define a scalar representation of the interaction called ”exotic quintessence”. This led us to a modified Friedmann equation with which we model a universe with baryonic matter, dark matter and dark energy contents. We made statistical adjustment of the parameters of this exotic model. In addition to this, we calculated the age of the universe and the redshift when it begins to accelerate, and also made a study of linear perturbations. Moreover we exactly solve the modified Einstein equation obtained in the exotic case with three fluids. Finally, we analyze models with conserved baryonic matter and dark matter in interaction with dark energy, where interaction is limited to produce ratios of energy densities of both dark components, asymptotically stable. | - |
| dc.description | Fil:Forte, Mónica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. | - |
| dc.format | application/pdf | - |
| dc.language | spa | - |
| dc.publisher | Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires | - |
| dc.rights | info:eu-repo/semantics/openAccess | - |
| dc.rights | http://creativecommons.org/licenses/by/2.5/ar | - |
| dc.source.uri | http://digital.bl.fcen.uba.ar/gsdl-282/cgi-bin/library.cgi?a=d&c=tesis&d=Tesis_4963_Forte | - |
| dc.subject | K ESSENCE | - |
| dc.subject | EXOTIC QUINTESSENCE | - |
| dc.subject | N-QUINTOM | - |
| dc.subject | COSMOLOGICAL INTERACTIONS | - |
| dc.subject | BIANCHI I | - |
| dc.subject | FRW | - |
| dc.subject | K ESENCIA | - |
| dc.subject | QUINTAESENCIA | - |
| dc.subject | N-QUINTOM | - |
| dc.subject | INTERACCIONES | - |
| dc.subject | BIANCHI I | - |
| dc.subject | FRW | - |
| dc.title | Escenarios cosmológicos en expansión acelerada | - |
| dc.title | Cosmological scenarios in accelerated expansion | - |
| dc.type | info:eu-repo/semantics/doctoralThesis | - |
| dc.type | info:ar-repo/semantics/tesis doctoral | - |
| dc.type | info:eu-repo/semantics/publishedVersion | - |
| Aparece en las colecciones: | FCEN - Facultad de Ciencias Exactas y Naturales. UBA | |
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