• Conference Object  

      Aspects of string cosmology 

      Kounnas, Costas; Toumbas, Nicolaos K. (Trieste, SISSA: Proceedings of Science., 2013)
      We review recent progress in string cosmology, where string dualities are applied so as to obtain complete cosmological evolutions, free of any essential singularities. Two classes of models are analyzed. The first class ...
    • Article  

      Cosmological constraints on Brans-Dicke theory 

      Avilez, A.; Skordis, C. (2014)
      We report strong cosmological constraints on the Brans-Dicke (BD) theory of gravity using cosmic microwave background data from Planck. We consider two types of models. First, the initial condition of the scalar field is ...
    • Article  

      Cosmology and fundamental physics with the Euclid satellite 

      Amendola, L.; Appleby, S.; Bacon, D.; Baker, T.; Baldi, M.; Bartolo, N.; Blanchard, A.; Bonvin, C.; Borgani, S.; Branchini, E.; Burrage, C.; Camera, S.; Carbone, C.; Casarini, L.; Cropper, M.; de Rham, C.; Di Porto, C.; Ealet, A.; Ferreira, P. G.; Finelli, F.; García-Bellido, J.; Giannantonio, T.; Guzzo, L.; Heavens, A.; Heisenberg, L.; Heymans, C.; Hoekstra, H.; Hollenstein, L.; Holmes, R.; Horst, O.; Jahnke, K.; Kitching, T. D.; Koivisto, T.; Kunz, M.; La Vacca, G.; March, M.; Majerotto, E.; Markovic, K.; Marsh, D.; Marulli, F.; Massey, R.; Mellier, Y.; Mota, D. F.; Nunes, N. J.; Percival, W.; Pettorino, V.; Porciani, C.; Quercellini, C.; Read, J.; Rinaldi, M.; Sapone, D.; Scaramella, R.; Skordis, C.; Simpson, F.; Taylor, A.; Thomas, S.; Trotta, R.; Verde, L.; Vernizzi, F.; Vollmer, A.; Wang, Y.; Weller, J.; Zlosnik, T. (2013)
      Euclid is a European Space Agency medium-class mission selected for launch in 2019 within the Cosmic Vision 2015 - 2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the ...
    • Article  

      Modified gravity and cosmology 

      Clifton, T.; Ferreira, P. G.; Padilla, A.; Skordis, C. (2012)
      In this review we present a thoroughly comprehensive survey of recent work on modified theories of gravity and their cosmological consequences. Amongst other things, we cover General Relativity, scalar-tensor, Einstein-æther, ...
    • Article  

      Open problems in string cosmology 

      Toumbas, Nicolaos K. (2010)
      Some of the open problems in string cosmology are highlighted within the context of the recently constructed thermal and quantum superstring cosmological solutions. Emphasis is given on the high temperature cosmological ...
    • Article  

      Testing general relativity with cosmology: a synopsis of the parametrized post-Friedmann approach 

      Ferreira, P. G.; Baker, T.; Skordis, C. (2014)
      More than half a century after the Chapel Hill meeting of 1957, the landscape of general relativity has been transformed. In relativistic cosmology we are entering an era in which we can seriously consider testing some of ...
    • Article  

      Thermal and quantum superstring cosmologies 

      Catelin-Jullien, T.; Kounnas, Costas; Partouche, Hervé; Toumbas, Nicolaos K. (2008)
      We consider four dimensional heterotic string backgrounds for which supersymmetry is spontaneously broken via the Scherk-Schwarz mechanism on an internal spatial cycle and by finite temperature effects. We concentrate on ...
    • Article  

      Thermal duality and non-singular cosmology in d-dimensional superstrings 

      Kounnas, Costas; Partouche, Hervé; Toumbas, Nicolaos K. (2012)
      We are presenting the basic ingredients of a stringy mechanism able to resolve both the Hagedorn instabilities of finite temperature superstrings as well as the initial singularity of the induced cosmology in arbitrary ...