Peculiar acceleration

Understand

It has been proposed recently to observe the change in cosmological redshift of distant galaxies or quasars with the next generation of large telescope and ultra-stable spectrographs (the so-called Sandage-Loeb test).

• Here we investigate the possibility of observing the change in peculiar velocity in nearby clusters and galaxies.
• This ``peculiar acceleration'' could help reconstructing the gravitational potential without assuming virialization.
• We show that the expected effect is of the same order of magnitude of the cosmological velocity shift.