Zobrazeno 1 - 10
of 171
pro vyhledávání: '"Boehmer, Christian"'
Publikováno v:
International Journal of Modern Physics D33, No. 11, 2430001 (2024)
We introduce a new class of two dimensional gravity models using ideas motivated by the Teleparallel Equivalent of General Relativity. This leads to a rather natural formulation of a theory that has close links with Jackiw-Teitelboim gravity. After i
Externí odkaz:
http://arxiv.org/abs/2404.18679
We study geodesics in Friedmann-Lema{\^\i}tre-Robertson-Walker (FLRW) cosmological models and give the full set of solutions. For azimuthal geodesics, in a closed universe, we give the angular distance travelled by a test particle moving along such a
Externí odkaz:
http://arxiv.org/abs/2404.18119
Publikováno v:
General Relativity and Gravitation 56, 75 (2024)
Cosmological models can be studied effectively using dynamical systems techniques. Starting from Brown's formulation of the variational principle for relativistic fluids, we introduce new types of couplings involving a perfect fluid, a scalar field,
Externí odkaz:
http://arxiv.org/abs/2404.05301
Autor:
Hansraj, Sudan, Hansraj, Chevarra, Mkhize, Njabulo, Errehymy, Abdelghani, Boehmer, Christian G.
Publikováno v:
Physics of the Dark Universe 44 (2024) 101443
The trace-free Einstein equations contain one equation less than the complete field equations. In a static and spherically symmetric spacetime, the number of field equations is thus reduced to two. The equation of pressure isotropy of general relativ
Externí odkaz:
http://arxiv.org/abs/2402.07620
Modern cosmology is closely linked to our understanding of radial null geodesics as these model the propagation of light signals through an expanding universe. Azimuthal geodesics, on the other hand, are perhaps best known for their relevance within
Externí odkaz:
http://arxiv.org/abs/2401.04597
Autor:
Boehmer, Christian G., Jensko, Erik
Publikováno v:
Fortschr. Phys. 2024, 72, 2300216
It is well known that the Einstein-Hilbert action in two dimensions is topological and yields an identically vanishing Einstein tensor. Consequently one is faced with difficulties when formulating a non-trivial gravity model. We present a new, intrin
Externí odkaz:
http://arxiv.org/abs/2308.01728
Publikováno v:
Universe 9 (2023) 4, 166
Modified gravity theories can be used for the description of homogeneous and isotropic cosmological models through the corresponding field equations. These can be cast into systems of autonomous differential equations because of their sole dependence
Externí odkaz:
http://arxiv.org/abs/2303.04463
Autor:
Boehmer, Christian G., Jensko, Erik
Publikováno v:
J. Math. Phys. 64, 082505 (2023)
The starting point of this work is the original Einstein action, sometimes called the Gamma squared action. Continuing from our previous results, we study various modified theories of gravity following the Palatini approach. The metric and the connec
Externí odkaz:
http://arxiv.org/abs/2301.11051
Autor:
Arun, K. G., Belgacem, Enis, Benkel, Robert, Bernard, Laura, Berti, Emanuele, Bertone, Gianfranco, Besancon, Marc, Blas, Diego, Böhmer, Christian G., Brito, Richard, Calcagni, Gianluca, Cardenas-Avendaño, Alejandro, Clough, Katy, Crisostomi, Marco, De Luca, Valerio, Doneva, Daniela, Escoffier, Stephanie, Ezquiaga, Jose Maria, Ferreira, Pedro G., Fleury, Pierre, Foffa, Stefano, Franciolini, Gabriele, Frusciante, Noemi, García-Bellido, Juan, Herdeiro, Carlos, Hertog, Thomas, Hinderer, Tanja, Jetzer, Philippe, Lombriser, Lucas, Maggio, Elisa, Maggiore, Michele, Mancarella, Michele, Maselli, Andrea, Nampalliwar, Sourabh, Nichols, David, Okounkova, Maria, Pani, Paolo, Paschalidis, Vasileios, Raccanelli, Alvise, Randall, Lisa, Renaux-Petel, Sébastien, Riotto, Antonio, Ruiz, Milton, Saffer, Alexander, Sakellariadou, Mairi, Saltas, Ippocratis D., Sathyaprakash, B. S., Shao, Lijing, Sopuerta, Carlos F., Sotiriou, Thomas P., Stergioulas, Nikolaos, Tamanini, Nicola, Vernizzi, Filippo, Witek, Helvi, Wu, Kinwah, Yagi, Kent, Yazadjiev, Stoytcho, Yunes, Nicolas, Zilhao, Miguel, Afshordi, Niayesh, Angonin, Marie-Christine, Baibhav, Vishal, Barausse, Enrico, Barreiro, Tiago, Bartolo, Nicola, Bellomo, Nicola, Ben-Dayan, Ido, Bergshoeff, Eric A., Bernuzzi, Sebastiano, Bertacca, Daniele, Bhagwat, Swetha, Bonga, Béatrice, Burko, Lior M., Compere, Geoffrey, Cusin, Giulia, da Silva, Antonio, Das, Saurya, de Rham, Claudia, Destounis, Kyriakos, Dimastrogiovanni, Ema, Duque, Francisco, Easther, Richard, Farmer, Hontas, Fasiello, Matteo, Fisenko, Stanislav, Fransen, Kwinten, Frauendiener, Jörg, Gair, Jonathan, Gergely, Laszlo Arpad, Gerosa, Davide, Gualtieri, Leonardo, Han, Wen-Biao, Hees, Aurelien, Helfer, Thomas, Hennig, Jörg, Jenkins, Alexander C., Kajfasz, Eric, Kaloper, Nemanja, Karas, Vladimir, Kavanagh, Bradley J., Klioner, Sergei A., Koushiappas, Savvas M., Lagos, Macarena, Poncin-Lafitte, Christophe Le, Lobo, Francisco S. N., Markakis, Charalampos, Martin-Moruno, Prado, Martins, C. J. A. P., Matarrese, Sabino, Mayerson, Daniel R., Mimoso, José P., Noller, Johannes, Nunes, Nelson J., Oliveri, Roberto, Orlando, Giorgio, Pappas, George, Pikovski, Igor, Pilo, Luigi, Podolsky, Jiri, Pratten, Geraint, Prokopec, Tomislav, Qi, Hong, Rastgoo, Saeed, Ricciardone, Angelo, Rollo, Rocco, Rubiera-Garcia, Diego, Sergijenko, Olga, Shapiro, Stuart, Shoemaker, Deirdre, Spallicci, Alessandro, Stashko, Oleksandr, Stein, Leo C., Tasinato, Gianmassimo, Tolley, Andrew J., Vagenas, Elias C., Vandoren, Stefan, Vernieri, Daniele, Vicente, Rodrigo, Wiseman, Toby, Zhdanov, Valery I., Zumalacárregui, Miguel
The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about the fundamental theory of nature at play in the extreme gravity regime, where the gravitational interaction is both strong and dynamical. In this white paper, the
Externí odkaz:
http://arxiv.org/abs/2205.01597
Publikováno v:
Eur. Phys. J. C 82, 500 (2022)
The field equations of modified gravity theories, when considering a homogeneous and isotropic cosmological model, always become autonomous differential equations. This relies on the fact that in such models all variables only depend on cosmological
Externí odkaz:
http://arxiv.org/abs/2201.09588