Confronting MOND and TeVeS with strong gravitational lensing over galactic scales: An extended survey

Abstract

The validity of MOND and TeVeS models of modified gravity has been recently tested by using lensing techniques, with the conclusion that a non-trivial component in the form of dark matter is needed in order to match the observations. In this work those analyses are extended by comparing lensing to stellar masses for a sample of nine strong gravitational lenses that probe galactic scales. The sample is extracted from a recent work that presents the mass profile out to a few effective radii, therefore reaching into regions that are dominated by dark matter in the standard (general relativity) scenario. A range of interpolating functions are explored to test the validity of MOND/TeVeS in these systems. Out of the nine systems, there are five robust candidates with a significant excess (higher that 50%) of lensing mass with respect to stellar mass, irrespective of the stellar initial mass function. One of these lenses (Q0957) is located at the centre of a galactic cluster. This system might be accommodated in MOND/TeVeS via the addition of a hot component, like a 2 eV neutrino, that contribute over cluster scales. However, the other four robust candidates (LBQS1009, HE1104, B1600, HE2149) are located in field/group regions, so that a cold component (CDM) would be required even within the MOND/TeVeS framework. Our results therefore do not support recent claims that these alternative scenarios to CDM can survive astrophysical data.

Testing Verlinde's emergent gravity in early-type galaxies

“…It has been shown to reproduce flat rotation curves of spiral galaxies without the need for DM, and naturally predicting the observed relation between galaxy rotation and luminosity (Tully & Fisher 1977;Sanders & McGaugh 2002) or baryonic mass (McGaugh 2012). Only a few MOND analyses have been carried out on early-type galaxies (ETGs; e.g., Cardone et al 2011;Ferreras et al 2012;Milgrom 2012;Sanders 2014). Recently, Tortora et al (2014c) have demonstrated that MOND is consistent with the central dynamics of ETGs if the stellar M/L are systematically larger in higher-velocity dispersion (σ) galaxies, when compared with those calculated from stellar populations, assuming a universal stellar IMF.…”

A survey of dark matter and related topics in cosmology

“…See also [37] and [38]. More recently, a survey on confronting MOND/TeVeS with strong gravitational lensing over galactic scales has been performed in [60]. The conclusion is that in order to accommodate all observations, a dark matter component is needed even in the MOND/ TeVeS framework.…”

“…The initial velocity of χ relative to the detector in question, denoted by v, is dominated by the galactic rotation of the solar system which is about 220 km/s. 60), 61) So the process can be treated 60) Note that the earth orbital speed is about 30 km/s and the maximal tangential speed due to the rotation of Earth around its axis is about 0.5 km/s. So to our lowest order estimate we neglect the earth motion.…”

“…The modified gravity (MOG) was proposed in 2006 [61] which has been tested against observations. For more comments, see [60].…”

Reconciliation of modified Newtonian dynamics and dark matter theory

“…Besides these numerous big problems, a long list of fundamental physics difficulties such as violating the conservation of momentum exist in MOND theory [29]. The relativistic version of MOND theory (TeVeS) is also not supported by recent gravitational lensing results in clusters [30].…”