CLASS MANUAL
Where to find information and documentation on CLASS?

Author: Julien Lesgourgues

  • For what the code can actually compute: all possible input parameters, all coded cosmological models, all functionalities, all observables, etc.: read the file explanatory.ini in the main CLASS directory: it is THE reference file where we keep track of all possible input and the definition of all input parameters. For that reason we recommend to leave it always unchanged and to work with copies of it, or with short input files written from scratch.

  • For the structure, style, and concrete aspects of the code: this documentation, especially the CLASS overview chapter (the extensive automatically-generated part of this documentation is more for advanced users); plus the slides of our CLASS lectures, for instance those from New York 2019 available at

    https://lesgourg.github.io/class-tour-NewYork.html

    An updated overview of available CLASS lecture slides is always available at

    http://lesgourg.github.io/courses.html

    in the section Courses on numerical tools.

  • For the python wrapper of CLASS: at the moment, the best are the "Usage I" and "Usage II" slides of the New York 2019 course,

    https://lesgourg.github.io/class-tour-NewYork.html

  • For the physics and equations used in the code: mainly, the following papers:

    • Cosmological perturbation theory in the synchronous and conformal Newtonian gauges

      C. P. Ma and E. Bertschinger.

      http://arxiv.org/abs/astro-ph/9506072

      10.1086/176550

      Astrophys. J. 455, 7 (1995)

    • The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes

      D. Blas, J. Lesgourgues and T. Tram.

      http://arxiv.org/abs/1104.2933 [astro-ph.CO]

      10.1088/1475-7516/2011/07/034

      JCAP 1107, 034 (2011)

    • The Cosmic Linear Anisotropy Solving System (CLASS) IV: efficient implementation of non-cold relics

      J. Lesgourgues and T. Tram.

      http://arxiv.org/abs/1104.2935 [astro-ph.CO]

      10.1088/1475-7516/2011/09/032

      JCAP 1109, 032 (2011)

    • Optimal polarisation equations in FLRW universes

      T. Tram and J. Lesgourgues.

      http://arxiv.org/abs/1305.3261 [astro-ph.CO]

      10.1088/1475-7516/2013/10/002

      JCAP 1310, 002 (2013)

    • Fast and accurate CMB computations in non-flat FLRW universes

      J. Lesgourgues and T. Tram.

      http://arxiv.org/abs/1312.2697 [astro-ph.CO]

      10.1088/1475-7516/2014/09/032

      JCAP 1409, no. 09, 032 (2014)

    • The CLASSgal code for Relativistic Cosmological Large Scale Structure

      E. Di Dio, F. Montanari, J. Lesgourgues and R. Durrer.

      http://arxiv.org/abs/1307.1459 [astro-ph.CO]

      10.1088/1475-7516/2013/11/044

      JCAP 1311, 044 (2013)

    • The synergy between CMB spectral distortions and anisotropies

      M. Lucca, N. Schöneberg, D. C. Hooper, J. Lesgourgues, J. Chluba.

      http://arxiv.org/abs/1910.04619 [astro-ph.CO]

      JCAP 02 (2020) 026

    • Optimal Boltzmann hierarchies with nonvanishing spatial curvature

      C. Pitrou, T. S. Pereira, J. Lesgourgues,

      http://arxiv.org/abs/2005.12119 [astro-ph.CO]

      Phys.Rev.D 102 (2020) 2, 023511

    Plus also some latex notes on specific sectors:

    Interactions between idm and idr are modelled by the ETHOS formalism of Cyr-Racine et al. [1512.05344]. This was introduced in Class v2.9 with a parametrisation described in

    • Constraining Dark Matter-Dark Radiation interactions with CMB, BAO, and Lyman-alpha

      M. Archidiacono, D. C. Hooper, R. Murgia, S. Bohr, J. Lesgourgues, M. Viel

      http://arxiv.org/abs/1907.01496 [astro-ph.CO]

      JCAP 10 (2019) 055

    In Class v3.2, this sector has been generalised to multi-interacting dark matter with three interaction channels (dark radiation, baryons, photons) and a parametrisation described in

    • Cosmological constraints on multi-interacting dark matter

      N. Becker, D. C. Hooper,F. Kahlhoefer, J. Lesgourgues, N. Schöneberg

      http://arxiv.org/abs/2010.04074 [astro-ph.CO]

      JCAP 02 (2021) 019