Konwersatorium im. J.Pniewskiego i L.Infelda

After the detection of the accelerated expansion of the Universe (Nobel prize 2011) and the introduction of an enigmatic “dark energy” component of the matter-energy content of the Universe the physical explanation of the nature of dark energy has become a major challenge for astronomers and physicists. The recent empirical determinations of the Universe expansion based on standard candles (Cepheids, Supernovae Ia) complicated even more our understanding of the Universe since they differ by about 4σ from the value obtained from Planck data and the ΛCDM model, which suggest that new physics might be required in the models. However before one can claim the revision in modern physics all systematic errors affected the determination of the expansion rate must be very carefully investigated and accuracy, and not only precision must be reached.

In my presentation I will discuss the most precise and accurate methods for cosmic distance determinations. I will also explain how these methods can be used to calibrate other long-range distance indicators, which allow us to calibrate Supernovae Ia. Finally I will discuss how accurately we expect to determine the expansion rate of the Universe in the near future, and how this will impact the current discrepancy between different values of the expansion rate of the Universe as obtained with different techniques.

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