Splicing Dark Matter Halos
(2024) ASTM32 20241Department of Physics
Astrophysics
- Abstract
- In this thesis, I study the evolution of individual dark matter halos as I change their environments. Dark matter halos at present day are traced back to their constituent particles in the initial conditions and inserted, or "spliced", into environments of differing distance to a large filament. Splicing retains all initial information of the halos evolution, allowing to probe the non-linear effects that filaments have on the evolution of dark matter halos. The novelty of my work lies in my use of controlled cosmological simulations to unravel the causal effect of filamentary structures on halo properties. I confirm that halo mass and radius are not strongly coupled to environmental factors and should be directly attainable from the... (More)
- In this thesis, I study the evolution of individual dark matter halos as I change their environments. Dark matter halos at present day are traced back to their constituent particles in the initial conditions and inserted, or "spliced", into environments of differing distance to a large filament. Splicing retains all initial information of the halos evolution, allowing to probe the non-linear effects that filaments have on the evolution of dark matter halos. The novelty of my work lies in my use of controlled cosmological simulations to unravel the causal effect of filamentary structures on halo properties. I confirm that halo mass and radius are not strongly coupled to environmental factors and should be directly attainable from the initial conditions. However, the orientation of such halos is highly non-linear and can not be predicted from analytical models. (Less)
- Popular Abstract
- The matter content of the Universe can be split up into 15% regular matter and 85% dark matter. The stars in the night sky, nebulae, galaxies, i.e, the objects we can actually see with our telescopes are all made up regular matter. Dark matter, on the other hand, does not give off light, which means that the vast majority of the mass in our Universe is unobservable. We can detect the presence of dark matter by studying its effects on galaxies, such as how they rotate and interact with one another, as well as how large clumps of dark matter bend light due to gravity. Currently, the best way to study dark matter is by using supercomputers which simulate the evolution of our Universe.
In the early Universe, dark matter pooled up into... (More) - The matter content of the Universe can be split up into 15% regular matter and 85% dark matter. The stars in the night sky, nebulae, galaxies, i.e, the objects we can actually see with our telescopes are all made up regular matter. Dark matter, on the other hand, does not give off light, which means that the vast majority of the mass in our Universe is unobservable. We can detect the presence of dark matter by studying its effects on galaxies, such as how they rotate and interact with one another, as well as how large clumps of dark matter bend light due to gravity. Currently, the best way to study dark matter is by using supercomputers which simulate the evolution of our Universe.
In the early Universe, dark matter pooled up into spheres called dark matter halos, and inside those halos inhabit galaxies. Our own Milky Way is surrounded by a dark halo much more massive than the gas and stars we see. Dark matter halos exist within a much larger framework called the cosmic web, named after its interconnected filamentary structure, which permeates the entire Universe. My thesis explores the way such filaments, through their long range gravitational fields, affect the evolution of dark matter halos. Specifically, I am looking at how properties such as mass, size, shape, and orientation of dark matter halos are changed as their environments change. I do this by using a technique I helped develop called splicing, which allows to disentangle the dark matter halo from its filament. The reason we might want to do that is explained by the following analogy:
Imagine a cat which was born and raised in two different parallel universes. The cat is raised by a loving family in one universe and in the other, is neglected. Obviously in both universes, the cat will grow to be the same size, the same color, and have the same genetic defects. We can therefore say that these properties are intrinsic to the cat. On the other hand, the cat which grew up in a loving family is much more likely to be trusting and affectionate, and will show less signs of aggression. The cat which grew up in neglect will become isolated and antisocial. Even though the initial cat is the same in both universes, some aspects of it has been drastically altered by a change in environment.
The same can be done with a dark matter halo where the same initial particles are the same across multiple parallel Universes, but the environment has been changes in such a way that the halo is "growing up" either close or far away from a filament. Doing so allows to find which properties are intrinsic to the initial particles, and which are affected by the filament. For example, I find that the mass of the halo at present day remains unaffected by a changing environment, but its orientation is heavily affected. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9159860
- author
- Storck, Anatole LU
- supervisor
-
- Corentin Cadiou LU
- Oscar Agertz LU
- organization
- course
- ASTM32 20241
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- cosmology, cosmic web, dark matter halos, angular momentum
- report number
- 2024-EXA225
- language
- English
- id
- 9159860
- date added to LUP
- 2024-11-05 09:54:32
- date last changed
- 2024-11-05 09:54:32
@misc{9159860,
abstract = {{In this thesis, I study the evolution of individual dark matter halos as I change their environments. Dark matter halos at present day are traced back to their constituent particles in the initial conditions and inserted, or "spliced", into environments of differing distance to a large filament. Splicing retains all initial information of the halos evolution, allowing to probe the non-linear effects that filaments have on the evolution of dark matter halos. The novelty of my work lies in my use of controlled cosmological simulations to unravel the causal effect of filamentary structures on halo properties. I confirm that halo mass and radius are not strongly coupled to environmental factors and should be directly attainable from the initial conditions. However, the orientation of such halos is highly non-linear and can not be predicted from analytical models.}},
author = {{Storck, Anatole}},
language = {{eng}},
note = {{Student Paper}},
title = {{Splicing Dark Matter Halos}},
year = {{2024}},
}