Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
The distribution of inelastic dark matter in the Sun
KTH, School of Engineering Sciences (SCI), Physics.ORCID iD: 0000-0001-5948-9152
KTH, School of Engineering Sciences (SCI), Physics.
2018 (English)In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 78, no 5, article id 386Article in journal (Refereed) Published
Abstract [en]

If dark matter is composed of new particles, these may become captured after scattering with nuclei in the Sun, thermalize through additional scattering, and finally annihilate into neutrinos that can be detected on Earth. If dark matter scatters inelastically into a slightly heavier (O(10-100)keV) state it is unclear whether thermalization occurs. One issue is that up-scattering from the lower mass state may be kinematically forbidden, at which point the thermalization process effectively stops. A larger evaporation rate is also expected due to down-scattering. In this work, we perform a numerical simulation of the capture and thermalization process in order to study the evolution of the dark matter distribution. We then calculate and compare the annihilation rate with that of the often assumed Maxwell–Boltzmann distribution. We also check if equilibrium between capture and annihilation is reached. We find that, unless the mass splitting is very small (≲50keV) and/or the dark matter has a sub-dominant elastic cross section, the dark matter distribution does not reach a stationary state, it is not isothermal, annihilation is severely suppressed, and equilibrium is generally not reached. We also find that evaporation induced by down-scattering is not effective in reducing the total dark matter abundance.

Place, publisher, year, edition, pages
Springer-Verlag New York, 2018. Vol. 78, no 5, article id 386
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-229624DOI: 10.1140/epjc/s10052-018-5863-4ISI: 000432927600001Scopus ID: 2-s2.0-85047251363OAI: oai:DiVA.org:kth-229624DiVA, id: diva2:1213828
Funder
Göran Gustafsson Foundation for Research in Natural Sciences and Medicine
Note

QC 20180605

Available from: 2018-06-05 Created: 2018-06-05 Last updated: 2019-05-16Bibliographically approved
In thesis
1. Dark Matter Phenomenology in Astrophysical Systems
Open this publication in new window or tab >>Dark Matter Phenomenology in Astrophysical Systems
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

There is now a great deal of evidence in support of the existence of a large amount of unseen gravitational mass, commonly called dark matter, from observations in astrophysical systems of sizes ranging from that of dwarf galaxies to the scale of the entire Universe. One of the most promising explanations for this unseen mass is that it consists of a species of unobserved elementary particles. An expected feature of particle dark matter is that it should form halos in the early Universe that cannot collapse due to its weak interactions with itself and baryonic matter. It is within these halos that galaxies, including the Milky Way, which is the galaxy that we inhabit, are thought to be born.Different methods to detect dark matter that originates from the galactic halo have been devised and these generally fall into the categories of direct and indirect detection. On Earth, direct detection experiments are employed to detect the recoiling atoms that are generated through the occasional scattering between halo dark matter particles with the detector material. The indirect search for dark matter is conducted by attempting to detect the standard model particles that may be produced as dark matter annihilates or decays and by looking for the effects that dark matter may have on astrophysical bodies. The aim of this thesis is to study the effects that dark matter may have in different astrophysical systems and how its properties can be determined should an effect that is due to dark matter be detected.The Sun currently experiences the solar composition problem, which is a mismatch between simulated and observed helioseismological properties of the Sun. A large abundance of dark matter introduces a new heat transfer mechanism that has been shown to offer a viable solution. This problem is discussed here in a particular model of dark matter where the dark matter halo is made up of equal numbers of particles and antiparticles. It is shown that dark matter arising from the thermal freeze-out mechanism might alleviate the problem, whereas only asymmetric dark matter models have previously been considered.If a dark matter signal is seen in a direct detection experiment, the determination of the dark matter properties will be plagued by numerous uncertainties related to the halo. It has been shown that many of these uncertainties can be eliminated by comparing signals in different direct detection experiments in what is called ``halo-independent" methods. These methods can also be used to predict the neutrino signal from dark matter annihilating in the Sun, further constraining DM properties, if a direct detection experiment detects a signal. This framework is here generalized to inelastic dark matter and the information concerning dark matter properties in a direct detection signal is discussed.When the Sun captures dark matter, thermalization is a process where dark matter particles lose their remaining kinetic energy after being captured and sink into the solar core. Evaporation due to collisions with high-energy solar atoms is also possible. For inelastic dark matter, it is expected that the thermalization process stops prematurely, which will have an effect on the expected neutrino signal from its annihilation. Moreover, evaporation may also be significant due transitions from the heavier to the lighter state. Here, the thermalization problem is discussed, and results from numerical simulations are presented that show the extent to which inelastic dark matter thermalizes and if evaporation has to be taken into account.A number of issues have been observed in dark matter halos at smaller scales when compared to results from large simulations. Dark matter that interacts strongly with itself has been proposed as a solution. There are a number of problems associated with these models that are excluded by other means. A particular model of inelastic dark matter interacting via a light mediator is analyzed here and shown to possible alleviate at least some of the problems associated with models of this kind.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2019. p. 95
Series
TRITA-SCI-FOU ; 2019:35
National Category
Physical Sciences
Research subject
Physics
Identifiers
urn:nbn:se:kth:diva-251394 (URN)978-91-7873-242-5 (ISBN)
Public defence
2019-06-13, FB52, AlbaNova universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:00 (English)
Opponent
Supervisors
Funder
Göran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, 1305BGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, 1404AGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, 1503Göran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of Technology, 1616
Note

QC20190517

Available from: 2019-05-17 Created: 2019-05-16 Last updated: 2019-05-17Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Blennow, MattiasClementz, Stefan

Search in DiVA

By author/editor
Blennow, MattiasClementz, Stefan
By organisation
Physics
In the same journal
European Physical Journal C
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 81 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf