Essays about: "cosmological constant"

Showing result 1 - 5 of 13 essays containing the words cosmological constant.

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

    University essay from Lunds universitet/Teoretisk partikelfysik

    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

  2. 2. High-Redshift Gamma-ray Bursts as seen by SVOM/ECLAIRs

    University essay from Luleå tekniska universitet/Rymdteknik

    Author : Miguel Llamas Lanza; [2021]
    Keywords : Gamma-ray Bursts; GRBs; compact objects; high energy; ECLAIRs; SVOM; high redshift; T90; detection biases;

    Abstract : Gamma Ray Burst (GRB) are very bright cosmological explosions signalling the catastrophic formation of a black hole. Therefore, they act like real light beacons that could be detected through-out the Universe and be used as probes to study the contents and phases of the early Universe. However, only a handful sample is known so far. READ MORE

  3. 3. A Tension between the Early and Late Universe: Could Our Underdense Cosmic Neighbourhood Provide an Explanation?

    University essay from Uppsala universitet/Institutionen för fysik och astronomi

    Author : Sveva Castello; [2021]
    Keywords : Cosmology; Hubble tension; local void;

    Abstract : In recent years, the increasingly precise constraints on the value of the Hubble constant, H0, have highlighted a discrepancy between the results arising from early-time and late-time measurements. A potential solution to this so-called Hubble tension is the hypothesis that we reside in a cosmic void, i.e. READ MORE

  4. 4. Do variations in the initial mass function affect galaxy evolution?

    University essay from Lunds universitet/Astronomi; Lunds universitet/Institutionen för astronomi och teoretisk fysik

    Author : Mateo Prgomet; [2020]
    Keywords : galaxy; galaxy formation; galaxy evolution; feedback; star formation; ultra faint dwarf galaxy; initial mass function; variations; universe; redshift; hydrodynamics; cosmology; zoomed-in simulations Galaxy formation and evolution; galaxy feedback; stellar feedback; IMF variations; cosmological zoomed-in simulations; Physics and Astronomy;

    Abstract : The initial mass function (IMF) describes the stellar mass distribution for a population of stars at birth. This parameter represents a topic of long standing discussion within astronomy due to its apparent insensitive nature to environmental conditions. However, in the last decade, significant evidence suggesting the contrary has been presented. READ MORE

  5. 5. Decay of solutions to the Klein-Gordon equation on some expanding cosmological spacetimes

    University essay from Lunds universitet/Teoretisk partikelfysik

    Author : Amol Sasane; [2019]
    Keywords : Klein-Gordon equation; general relativity; FLRW models; Schwarzschild-de Sitter; Reissner-Nordström-de Sitter; Physics and Astronomy;

    Abstract : The decay of solutions to the Klein-Gordon equation is studied in two expanding cosmological spacetimes, namely (1) the de Sitter universe in flat Friedmann-Lemaitre-Robertson-Walker (FLRW) form, and (2) the cosmological region of the Reissner-Nordström-de Sitter (RNdS) model. Using energy methods, for initial data with finite higher order energies, bounds on the decay rates of the solution are obtained. READ MORE