A NEW ESTIMATOR OF THE DECELERATION PARAMETER FROM GALAXY ROTATION CURVES

作者：van Putten Maurice H P M^*

来源：Astrophysical Journal, 2016, 824(1): 43.

DOI：10.3847/0004-637X/824/1/43

• cosmological parameters
• dark energy
• dark matter
• galaxies: kinematics and dynamics

The nature of dark energy can be probed by the derivative Q = dq(z)/dz vertical bar(0) at redshift z = 0 of the deceleration parameter q(z). It is probably static if Q < 1 or dynamic if Q > 2.5, supporting Lambda CDM or Lambda =(1 - q)H-2, respectively, where H denotes the Hubble parameter. We derive q = 1 - (4 pi a(0)/cH)(2), enabling a determination of q(z) by measuring Milgrom's parameter, a(0)(z), in galaxy rotation curves, equivalent to the coefficient A in the Tully-Fisher relation V-c(4) = AM(b) between a rotation velocity V-c and a baryonic mass M-b. We infer that dark matter should be extremely light, with clustering limited to the size of galaxy clusters. The associated transition radius to non-Newtonian gravity can conceivably be probed in a freefall Cavendish-type experiment in space.

• 出版日期2016-6-10
• 单位中国科学院理论物理研究所