Universitat de Barcelona
Now showing items 1-20 of 25
For ninety years we have known that our universe is in expansion. Cosmological data favor an unknown form of intrinsic and fundamental uniform energy contributing approximately 68% of the total energy budget in the current ...
This thesis has as a main purpose the determination of the chemical composition of Open Clusters for the study of the chemical gradients in the Galactic disc with: Galactocentric radius, position above the plane, and ...
Turbulence, magnetic fields and gravity driven flows are important for the formation of new stars. Although magnetic fields have been proven to be important in the formation of stars, only a few works have been done ...
In this thesis we have developed a tool for the computation of non-thermal emission in astrophysical sources. The code reads the hydrodynamic data coming from relativistic hydrodynamic simulations and compute the injection, ...
The work presented in this Ph.D. thesis is mostly related to the measurement and interpretation of the cross-correlation of different species. This is achieved using spectroscopic data from the BOSS survey of which I am a ...
[eng] The Cosmological Constant, Λ, has been a controversial element in theoretical physics and cosmology since its introduction by Einstein in his field equations in 1917. Despite maintaining an irregular reputation over ...
Open clusters are groups of stars, gravitationally bound together, that were born from the same molecular cloud and, thus, share similar positions, kinematics, ages and metallicities. Traditional methods to detect open ...
Star formation is a fundamental and still largely unsolved problem of astrophysics and cosmology. Its complexity stems from the complex interaction of turbulence, magnetic fields and gravity, and from the onset of different ...
Cosmology is the study of the origin and evolution of our Universe as a whole. Even if the theoretical framework of Cosmology was developed a century ago, with the formulation of General Relativity by Albert Einstein, it ...
The work we present in this manuscript revolves around the use of quasar spectra to probe the Universe. Absorption features in the electromagnetic spectrum of bright distant quasars by ionized hydrogen give us access to ...
[eng] Despite the successes of the cosmological ΛCDM model and having entered the "Precision Era of Cosmology" there are still open questions. The principal model ingredients, ΛCDM, contribute to ~95% of the total energy ...
This thesis has as an objective the study of very energetic phenomena in the central regions of active galaxies. Intense star formation is triggered by mergers of galaxies, and the funneling of large quantities of gas ...
En aquesta tesi s’estudien diferents models cosmològics, tots ells caracteritzats per considerar, de manera efectiva, una lleu evolució temporal de l’Energia Fosca, en contrast amb l’actual model estàndard de la cosmologia. ...
Some binary systems consisting of a compact object, which can be either a neutron star or a black hole, and typically a non-degenerate companion star, have been shown to emit broadband radiation from radio up to gamma-ray ...
The proper understanding of the equation of state (EoS) of highly asymmetric nuclear matter is essential when studying systems such as neutron stars (NSs). Using zero-range Skyrme interactions and finite-range interactions ...
In this thesis we study several open problems using Numerical Relativity on asymptotically Anti-de Sitter (AdS) spacetimes. The understanding of the dynamics of AdS is interesting not only because of pure theoretical reasons ...
This thesis has been devoted to the study of the gravitational collapse of spherically symmetric perturbations on a Friedman-Robertson-Walker (FRW) universe filled by a perfect fluid. Large cosmological perturbations ...
In this thesis, we are aimed to better understand the massive star formation process paying special attention to the role of the magnetic field. To do this, we will carry out a multi-scale analysis with a double approach, ...
The existence of black holes that go beyond the mass given by their stellar origin has been known for some time. On the lower end, a subset of primordial black holes (PBHs) could form all of the dark matter with individually ...
The standard cosmological model, ΛCDM, with the addition of an early inflationary phase, provides an accurate description of a nearly flat and homogeneous Universe, at large scales, which expands at an accelerated ...
