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591. WE-Heraeus-Seminar on Astrophysics, Clocks and Fundamental Constants (ACFC 2015)

The fundamental constants play a central role in our understanding of nature and the universe. They appear in the laws and equations of quantum mechanics, relativity, atomic, nuclear, and particle physics, but for all that we know little about them. It is not clear whether they are really constant neither if they are really fundamental or whether some of them could be derived from a deeper theory that is yet to be found. A main topic of this seminar is the question of the constancy of the constants and the search for conceivable variations in time and space, as they are predicted by certain theories and models of cosmological evolution.

From the cosmological and astrophysics side the new PLANCK satelite data give unprecedented information of the fluctuation in the early universe leading to variations in the fundamental constants. The unambiguous discovery of the Higgs particle and determination of its parameters has been one of the most awaited events and the description of the Higgs mechanism was recently awarded with a Nobel prize. A publication on the discovery of B-modes, a kind of fossil gravitational waves, has appeared and cosmologically important observations of distant supernovae were awarded by a Nobel prize. Precision tests of general relativity have demonstrated such accuracy that they are sensitive now to a variation of the solar mass. It plays a crucial role because it is a unit to measure in particular the masses of neutron stars.

Quantum optics and atomic clocks demonstrated a tremendous progress in recent years which was awarded by a Nobel prize. There has been a notable progress as well in atomic-interferometer measurements of various properties, such as gravity. Trapping particles and ions allows improving accuracy of determination of their parameters.

The metrological community is discussing the adoption of a new version of the International system of units, where all units should be based on fundamental constants. The activities in determination of the Planck, Avogadro and Boltzmann constants have produced a number of important results. There has been also an important progress in spectroscopy of exotic atoms. In particular, we expect soon new results on laser spectroscopy of muonic and antiprotonic atoms.

The seminar aims at an interdisciplinary exchange between scientists working with astrophysical observations and on laboratory experiments, interested in the foundations of physics and metrology and precision experimental techniques. In addition to a rich program of invited talks by renowned colleagues a poster session together with a mini presentation session will allow all participants to present their work. There will be an award for the best poster presentation.

Topics include:

  • Astrophysics, cosmology and general relativity
  • Particle physics
  • Quantum optics, atomic clocks and precision spectroscopy
  • Astrophysical search for variation of constants
  • Determination of fundamental constants