2. Dark energy with GMT
( 2020)
From Lucas Macri

3. Sketch of the timeline of the Universe in the ΛCDM model
Sketch of the timeline of the Universe in the ΛCDM model. The accelerated expansion in the last third of the timeline represents the dark-energy dominated era.

4. Variation of Fundamental Constants?
Quasar spectra mostly have a precision of 10-7 (corresponding to m/s), however recently one measurement at the 1m/s was done
QSO emit white light
Light is absorbed in galaxy(ies) on its way to earth
Absorption lines are redshifted
Ratio of fine structure lines gives value of alpha

5. Simulated spectrum of a high redshift quasar with z=3

6. Comb calibrated stellar Spectra
T. Wilken et al., Nature 485, 611 (2012)

7. Direct detection of expansion
400 nights of GMT time over 20 years
acceleration
From “Cosmic Dynamics in the Era of Extremely Large Telescopes”
deceleration
5x109 yr
8x109 yr
1x1010 yr
1.1x1010 yr
1.2x1010 yr
1.37x1010 yr
CMB
Z=1000