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Explore the concept and study for measuring the cosmic differential expansion to choose between universe models. Sandage's predictions for galaxy deceleration form part of the theory. Discover new observations like VLT-UVES and Keck HIRES of QSOs, accurate exoplanet measurements using HARPS, and ELT collaboration. The experiment aims for bias-free determination of cosmological parameters independent of evolutionary effects. Cosmic signals, epoch emissions, and actual epochs play crucial roles. Exciting projects include studying terrestrial planets in extra-solar systems and the cosmological variation of the fine-structure constant.
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Concept study for measuring the COsmic Differential EXpansion
The Experiment ”It should be possible to choose between various models of the expanding universe if the deceleration of a given galaxy could be measured. Precise predictions of the expected change in z=dl/l0 for reasonable observing times (say 100 years) is exceedingly small. Nevertheless, the predictions are interesting, since they form part ofthe available theory for the evolution of the universe” Sandage 1962 ApJ 136,319 Sandage predictions: z=0.4, k=+1 dz/dt = -0.73 cm /sec/year k= -1 -0.3 k= 0 -0.59 Steady state +0.92
What’s new • VLT-UVES & Keck HIRES observed hundreds of QSOs at High Res ( 40000), z between 2 and 5, V=16-18 • Exoplanets (HARPS) long term accuracy 1m/s, short term (hours) 0.1m/s (and largely understood) • ELT (100m)
Collaboration: ESO-Cambridge-Geneve-Trieste • About 25 people involved, 5 Work Packages Study Management Experiment Science Case Science Methodology Parallel Science Instrument Concept
cosmic signal te=emission epoch t0=actual epoch
Direct measurement • Bias-free determination of cosmological parameters • Different redshift (CMB, SNIa) • Not dependent from evolutionary effects of sources
Cosmological Variation of the Fine-structure Constant Outstanding projects Terrestrial planets in extra-solar systems Primordial nucleosynthesis, Q-H phase (?)