Sökning: "Gravity"

Visar resultat 1 - 5 av 356 avhandlingar innehållade ordet Gravity.

1. 1. Was Einstein Wrong? : Theoretical and observational constraints on massive gravity

   Författare :Marcus Högås; Edvard Mörtsell; David Mota; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Gravity; Massive gravity; Bimetric gravity; Cosmology; Gravitational collapse; Gravitational waves; Observational constraints; Theoretical Physics; teoretisk fysik;

   Sammanfattning : For more than a century, Einstein's theory of general relativity has described gravitational phenomena with astonishing precision. However, for the theory to fit observations we need to add two elusive substances: dark energy and dark matter. Together they add up to 95% of the energy budget of the Universe. LÄS MER

3. 2. Gravitational collapse in bimetric gravity

   Författare :Marcus Högås; Edvard Mörtsell; Tomi Koivisto; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bimetric gravity; bigravity; modified gravity; gravitational collapse; Bimetrisk gravitation; modifierad gravitation; gravitationskollaps; teoretisk fysik; Theoretical Physics;

   Sammanfattning : Einstein’s theory of general relativity has been the prevailing theory of classical gravity for over a century. Its observational consistency is unparalleled. There are however a few (arguably) serious short-comings. LÄS MER

4. 3. Cosmic tests of massive gravity

   Författare :Jonas Enander; Edvard Mörtsell; Stefan Hofmann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Modified gravity; massive gravity; cosmology; dark energy; dark matter; fysik; Physics;

   Sammanfattning : Massive gravity is an extension of general relativity where the graviton, which mediates gravitational interactions, has a non-vanishing mass. The first steps towards formulating a theory of massive gravity were made by Fierz and Pauli in 1939, but it took another 70 years until a consistent theory of massive gravity was written down. LÄS MER

5. 4. New Techniques for Estimation of Source Parameters : Applications to Airborne Gravity and Pseudo-Gravity Gradient Tensors

   Författare :Majid Beiki; Laust Pedersen; Mehrdad Bastani; Mark Pilkington; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gravity gradient tensor; pseudo-gravity; magnetic field; eigenvector analysis; least squares algorithm; strike direction; source parameter estimation; analytic signal; Euler deconvolution; joint inversion; infinite dike model; geological contact model; Solid earth physics; Fasta jordens fysik; Geophysics with specialization in Solid Earth Physics; Geofysik med inriktning mot fasta jordens fysik;

   Sammanfattning : Gravity gradient tensor (GGT) data contains the second derivatives of the Earth’s gravitational potential in three orthogonal directions. GGT data can be measured either using land, airborne, marine or space platforms. LÄS MER

7. 5. Stringed along or caught in a loop? : Philosophical reflections on modern quantum gravity research

   Författare :Keizo Matsubara; Lars-Göran Johansson; Holger Lyre; Uppsala universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; quantum gravity; string theory; loop quantum gravity; philosophy of physics; philosophy of science; scientific realism; structural realism; multiverse; thought experiments; Theoretical Philosophy; Teoretisk filosofi;

   Sammanfattning : A number of philosophical questions, all connected to modern research in quantum gravity, are discussed in this dissertation.The goal of research in quantum gravity is to find a quantum theory for gravitation; the other fundamental forces are already understood in terms of quantum physics. LÄS MER