Sökning: "Edvard Mörtsell"

Visar resultat 6 - 10 av 10 avhandlingar innehållade orden Edvard Mörtsell.

1. 6. Sources of Dust Extinction in Type Ia Supernovae : Measurements and constraints from X-rays to the Infrared

   Författare :Joel Johansson; Edvard Mörtsell; Ariel Goobar; Rahman Amanullah; Bruno Leibundgut; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; supernovae; interstellar dust; circumstellar dust; cosmology; fysik; Physics;

   Sammanfattning : The use of Type Ia supernovae (SNe Ia) as distance indicators is essential for studying the expansion history of the Universe and for exploring the nature of dark energy. However, a lack of understanding of the progenitor systems and the empirically derived colour-brightness corrections represent severe limitations for SNe Ia as cosmological probes. LÄS MER

3. 7. Constraints and symmetries in theories of interacting spin-2 fields

   Författare :Anders Lundkvist; Fawad Hassan; Edvard Mörtsell; Antonio Padilla; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; modified gravity; bimetric theory; spin-2 fields; classical field theory; partially massless symmetry; teoretisk fysik; Theoretical Physics;

   Sammanfattning : The Hassan-Rosen bimetric theory describes two interacting spin-2 fields, one massless and one massive. In this thesis, a complete canonical analysis of this theory is performed in the metric formulation and all constraints are computed. LÄS MER

4. 8. Investigating the Dark Universe through Gravitational Lensing

   Författare :Teresa Riehm; Ariel Goobar; Edvard Mörtsell; Erik Zackrisson; Joachim Wambsganss; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cosmology; gravitational lensing; dark matter; galaxies; galaxy clusters; Astronomy; Astronomi; Astronomy; astronomi;

   Sammanfattning : A variety of precision observations suggest that the present universe is dominated by some unknown components, the so-called dark matter and dark energy. The distribution and properties of these components are the focus of modern cosmology and we are only beginning to understand them. LÄS MER

5. 9. Symmetries and black holes in Hassan–Rosen bimetric theory

   Författare :Francesco Torsello; Edvard Mörtsell; Mikael von Strauss; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; teoretisk fysik; Theoretical Physics;

   Sammanfattning : The Hassan–Rosen bimetric theory is an extension of general relativity which considers the interaction between two metric fields defined on the same differentiable manifold. Self-accelerating cosmologies are exact solutions of this theory, and this makes it interesting to explore. LÄS MER

7. 10. Theoretical and numerical bimetric relativity

   Författare :Francesco Torsello; Edvard Mörtsell; Eugeny Babichev; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spin-2 fields; extension of general relativity; ghost-free bimetric theory; Hassan–Rosen bimetric relativity; numerical relativity; teoretisk fysik; Theoretical Physics;

   Sammanfattning : General relativity (GR) is the standard physical theory describing gravitational interactions. All astrophysical and cosmological observations are compatible with its predictions, provided that unknown matter and energy components are included. These are called dark matter and dark energy. LÄS MER