Essays about: "universums expansion"

Showing result 1 - 5 of 9 essays containing the words universums expansion.

  1. 1. Quantum Gauge Fields in Cosmology: Cosmic Inflation and Gravitational Waves

    University essay from Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Emma Hermansson; [2022]
    Keywords : Physics and Astronomy;

    Abstract : In this thesis, the consequences of introducing Yang-Mills fields into cosmology are investigated. This is done by the effective action approach, in which the coupling constant is allowed to depend on the quantum fields. READ MORE

  3. 2. Galaxies as Clocks and the Universal Expansion

    University essay from KTH/Fysik

    Author : Anders Ahlström Kjerrgren; [2021]
    Keywords : cosmology; cosmic chronometers; universal expansion; Hubble parameter; differential ages; galaxy age; relative age; cosmic time; chi-square minimization; monte carlo sampling; gaussian processes; kosmologi; kosmisk kronometer; universums expansion; Hubbleparametern; differentiell ålder; galaxålder; relativ ålder; kosmisk tid; chi-2-minimering; monte carlo-sampling; gaussiska processer;

    Abstract : The Hubble parameter H(z) is a measure of the expansion rate of the universe at redshift z. One method to determine it relies on inferring the slope of the redshift with respect to cosmic time, where galaxy ages can be used as a proxy for the latter. This method is used by Simon et al. READ MORE

  4. 3. Searching for signatures of compositeness of the Higgs boson

    University essay from Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Mårten Bertenstam; [2021]
    Keywords : two-Higgs-doublet model; composite Higgs model; composite two-Higgs-doublet model; phase transition; cosmological phase transition; electroweak phase transition; gravitational waves; gravitational wave background; Physics and Astronomy;

    Abstract : In this master thesis we consider some phenomenological aspects of two-Higgs-doublet models, both elementary and composite ones. The emphasis is on calculating and understanding first order phase transitions in such models, constrained to be in agreement with existing collider data on the Higgs sector. READ MORE

  5. 4. A Machine Learning Approach for Comprehending Cosmic Expansion

    University essay from KTH/Fysik

    Author : Ludvig Doeser; [2021]
    Keywords : Cosmology; Cosmic expansion; Galaxy Images; Machine learning; Kosmologi; kosmisk expansion; galaxbilder; maskininlärning;

    Abstract : This thesis aims at using novel machine learning techniques to test the dynamics of the Universe via the cosmological redshift-distance test. Currently, one of the most outstanding questions in cosmology is the physical cause of the accelerating cosmic expansion observed with supernovae. READ MORE

  6. 5. Nonequilibrium gauge field in Two Particle Irreducible real time formalism

    University essay from Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation; Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

    Author : Rasmus Hansen; [2019]
    Keywords : Gauge field; non-equilibrium; quantum field theory; Physics and Astronomy;

    Abstract : The purpose of this thesis is to study what effect a photon field has on the equations of motion and the decay of a charged scalar field in thermal equilibrium at finite temperature and outside of thermal equilibrium. To do this we calculate the two-particle irreducible effective action for the mean fields and propagators and derive their equations of motion. READ MORE