Sökning: "gravitational collapse"

Visar resultat 1 - 5 av 10 uppsatser innehållade orden gravitational collapse.

1. 1. Gravitational Collapse of a Massless Scalar Field in a Theory of Minimally Modified Gravity

   Master-uppsats, KTH/Fysik

   Författare :Atabak Fathe Jalali; [2024]
   Nyckelord :Theoretical physics; astrophysics; modified gravity; minimally modified gravity; gravitational collapse; VCDM; scalar collapse; apparent horizon; numerical relativity; Teoretisk fysik; astrofysik; modifierad gravitation; minimalt modifierad gravitation; gravitationskollaps; VCDM; skalär kollaps; uppenbar horisont; numerisk relativitet;

   Sammanfattning : This thesis explores the spherically symmetric gravitational collapse of a massless scalar field in a minimally modified gravity theory denoted VCDM (V replaces $\Lambda$ in the $\Lambda$CDM abbreviation), a class of theories propagating the same degrees of freedom as general relativity at the expense of broken 4D diffeomorphism invariance. Numerical evolution of the equations of motion reveals that for small initial scalar profile amplitudes, no black hole forms from the collapse. LÄS MER

3. 2. Matter-streams as sources of the Kerr metric

   Master-uppsats, Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

   Författare :Julian Boy; [2022]
   Nyckelord :General Relativity; Black holes; Physics; Kerr metric; Physics and Astronomy;

   Sammanfattning : An introduction to the thin-shell formalism and distributional approach to General Relativity is provided. The formalism is utilized to investigate possible distributions of matter that can act as a source to the Kerr metric. LÄS MER

4. 3. The visibility of double neutron star binaries to LISA

   Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Anatole Storck; [2021]
   Nyckelord :gravitational waves; LISA; neutron stars; orbital simulations; Runge-Kutta method; Physics and Astronomy;

   Sammanfattning : Double neutron star binaries (DNSBs) in the mHz gravitational wave (GW) regime are an important group of objects which the GW detector LISA will be able to observe. The detection and parametrization of these objects will help develop our current understanding of neutron star formation and evolution. LÄS MER

5. 4. Spherically Symmetric Gravitational Collapse

   Kandidat-uppsats, Lunds universitet/Teoretisk partikelfysik - Geonomgår omorganisation

   Författare :Lucas Bring; [2021]
   Nyckelord :gravitational collapse; gravitation; general relativity; black hole; Schwarzschild coordinates; Gullstrand-Painleve coordinates; Friedmann-Robertson-Walker metric; finite-time collapse; Physics and Astronomy;

   Sammanfattning : This thesis presents a derivation of the equation of motion of particles in a dust star, as it undergoes collapse. This is done by finding exact solutions to the Einstein field equations. We follow the original work by Oppenheimer and Snyder, starting from the general spherically symmetric metric in comoving coordinates. LÄS MER

7. 5. Chaos in Stellar Dynamics - Outcomes of Binary-Single interactions in Globular Clusters

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation; Lunds universitet/Institutionen för astronomi och teoretisk fysik - Genomgår omorganisation

   Författare :Lucas Hellström; [2020]
   Nyckelord :Stellar Dynamics; Binary-Single interactions; Dynamical encounters; Additional processes; Physics and Astronomy;

   Sammanfattning : Gravitational encounters between a single star and a binary system can frequently occur in the cores of dense stellar systems like globular clusters. These three-body scattering encounters can lead to a variety of outcomes since the energy of the binary components can be exchanged with the interacting single star. LÄS MER