Dynamics of Nearby Groups of Galaxies: the role of the cosmological constant

Understand

(context) Different cosmological data are consistent with an accelerated expansion produced by an exotic matter-energy component, dubbed "dark-energy''.

• A cosmological constant is a possibility since it satisfies most of the observational constraints.
• (aims) In this work, the consequences of such a component in the dynamics of groups of galaxies is investigated, aiming to detect possible effects in scales of the order of few Mpc.
• (methods) The Lema\^itre-Tolman model was modified by the inclusion of the cosmological constant term and, from the numerical solution of the equations of motion, a velocity-distance relation was obtained.