Exploració per tema "Cosmology"
Ara es mostren els items 21-40 de 81
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Design of an expanding cosmological background for the moving punctures approach to numerical relativity
(Universitat Politècnica de Catalunya, 2019-05-31)
Treball Final de Grau
Accés obert
Realitzat a/amb: Center for Relativistic AstrophysicsGravitational waves astronomy is a new field ushered in by the first detection of a par of merging black holes. Numerical relativity is the only tool capable of solving Einstein’s equations for the the dynamics and resulting ... -
Different reheating mechanisms in quintessence inflation
(American Physical Society (APS), 2019-02-11)
Article
Accés obertDifferent well-known ways to reheat the Universe, such as instant preheating, the creation of particles nearly or conformally coupled with gravity, or from the decay of products of a curvaton field, are revisited and ... -
Do old Testament texts substantiate Geocentrism?
(2020-12-31)
Article
Accés obertWe often read excerpts from the Old Testament that appear to evince an understanding of the Earth as the centre of creation, with the Sun revolving around it. That conception is commonly known as Geocentrism (¿e¿¿e¿t¿¿sµ¿¿), ... -
El Big Bang i l'Univers primitiu: expansió i abundàncies primordials
(Universitat Politècnica de Catalunya, 2020-06-22)
Treball Final de Grau
Accés obertL’objectiu del present treball és l’estudi i caracterització de l’Univers primitiu, mitjançant l’anàlisi d’algunes de les evidències experimentals en què es fonamenta la teoria del Big Bang. El projecte consta de dos blocs ... -
Evolution and dynamics of a matter creation model
(2016-05-01)
Article
Accés obertIn a flat Friedmann–Lemaître–Robertson–Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced ‘adiabatic’ matter creation. To demonstrate how matter creation works well ... -
Expectations for the high-energy neutrino detection from starburst galaxies with KM3NeT/ARCA
(arXiv, 2021)
Text en actes de congrés
Accés obertStar-forming galaxies (SFGs) and starburst galaxies (SBGs) are extragalactic sources which could produce high-energy neutrinos. In principle, they could play a rather important role for explaining at least a sizeable part ... -
Explotaciones mineras en cuerpos celestes
(Universitat Politècnica de Catalunya, 2021-09-15)
Treball Final de Grau
Accés obertThis thesis focuses on the concept of space mining, analysing its current state and, subsequently, comparing it to land-based mining. Defining the negative impacts of traditional mining, such as environmental and social ... -
Finite-time cosmological singularities and the possible fate of the Universe
(Elsevier, 2023-09-14)
Article
Accés restringit per política de l'editorialSingularities in any physical theory are either remarkable indicators of the unknown underlying fundamental theory, or indicate a change in the description of the physical reality. In General Relativity there are three ... -
Gravitational Particle Production in Massive Chaotic Inflation and the Moduli Problem
(2012-02)
Article
Accés restringit per política de l'editorialParticle production from vacuum fluctuations during inflation is briefly revisited. The moduli problem occurring with light particles produced at the end of inflation is addressed, namely the fact that some results are in ... -
High-energy reconstruction for single and double cascades using the KM3NeT detector
(arXiv, 2021)
Text en actes de congrés
Accés obertThe discovery of a high-energy cosmic neutrino flux has paved the way for the field of neutrino astronomy. For a large part of the flux, the sources remain unidentified. The KM3NeT detector, which is under construction in ... -
Homothetic motions and Newtonian cosmology
(2014-05-07)
Article
Accés restringit per política de l'editorialWe construct a homothetic covariant Newtonian gravitation theory which unifies inertial homothetic forces and gravitational fields. This is achieved through an equivalence principle based on a local homothetic frame of ... -
How can holonomy corrections be introduced in f(R) gravity?
(2014-07-08)
Article
Accés obertWe study the introduction of holonomy corrections in f(R) gravity. We will show that there are infinitely many ways, as many as canonical transformations, to introduce this kind of corrections, depending on the canonical ... -
Inflationary potential as seen from different angles: model compatibility from multiple CMB missions
(IOP Publishing, 2023-09)
Article
Accés obertThe cosmic microwave background (CMB) temperature and polarization anisotropies, as observed by independent astronomical missions such as WMAP, Planck, and most recently the Atacama Cosmology Telescope and the South Pole ... -
KM3NeT/ARCA sensitivity to transient neutrino sources
(arXiv, 2021)
Text en actes de congrés
Accés obertThe KM3NeT Collaboration is constructing a km3 -volume neutrino telescope in the Mediterranean sea, ARCA (Astroparticle Research with Cosmics in the Abyss), for the detection and subsequent study of high-energy cosmic ... -
La eterna historia
(1995-12)
Article
Accés obert -
Limiting curvature mimetic gravity and its relation to Loop Quantum Cosmology
(2019-04-01)
Article
Accés obertConsidering as usual that the underlying geometry of our universe is well described by the spatially flat Friedmann–Lemaître–Robertson–Walker line element, we review how the background of holonomy corrected Loop Quantum ... -
Massive black hole accretion using Numerical Relativity
(Universitat Politècnica de Catalunya, 2023-05-26)
Treball Final de Grau
Accés obert
Realitzat a/amb: University of Texas at AustinEn els darrers anys s’han detectat quàsars amb un desplaçament al vermell z > 7 i masses superiors a 10^9 masses solars (M⊙). L’existència d’objectes tan massius en èpoques tan primerenques de l’univers desafia les teories ... -
Matter Bounce Scenario in F(T) gravity
(2016)
Article
Accés obertIt is shown that teleparallel F(T) theories of gravity combined with holonomy corrected Loop Quantum Cosmology (LQC) support a Matter Bounce Scenario (MBS) which is a potential alternative to the inflationary paradigm. The ... -
Modelos cosmológicos en el marco de la teoría general de la relatividad
(Universitat Politècnica de Catalunya, 2016-06-29)
Treball Final de Grau
Accés obertDetailed work about relativistic cosmology: exposition of the principles and postulates, description of the geometry of spacetime and its matter contents, Hubble's law from a relativistic point of view, analysis of the ... -
Muon bundle reconstruction with KM3NeT/ORCA using graph convolutional networks
(arXiv, 2021)
Text en actes de congrés
Accés obertKM3NeT/ORCA is a water-Cherenkov neutrino detector, currently under construction in the Mediterranean Sea at a depth of 2450 meters. The project’s main goal is the determination of the neutrino mass hierarchy by measuring ...