Can the clustered dark matter and the smooth dark energy arise from the same scalar field

By Thanu Padmanabhan, T. R. Choudhury. 2002

410 citations recorded by the source corpus.

Cosmological observations suggest the existence of two different kinds of energy densities dominating at small $(\ensuremath{\lesssim}500\mathrm{Mpc})$ and large $(\ensuremath{\gtrsim}1000\mathrm{Mpc})$ scales. The dark matter component, which dominates at small scales, contributes ${\ensuremath{\Omega}}_{m}\ensuremath{\approx}0.35$ and has an equation of state $p=0,$ while the dark energy component, which dominates at large scales, contributes ${\ensuremath{\Omega}}_{V}\ensuremath{\approx}0.65$ and has an equation of state $p\ensuremath{\simeq}\ensuremath{-}\ensuremath{\rho}.$ It is usual to postulate weakly interacting massive particles (WIMPs) for the first component and some form of scalar field or cosmological constant for the second component. We explore the possibility of a scalar field with a Lagrangian $L=\ensuremath{-}V(\ensuremath{\varphi})\sqrt{1\ensuremath{-}{\ensuremath{\partial}}^{i}\ensuremath{\varphi}{\ensuremath{\partial}}_{i}\ensuremath{\varphi}}$ acting as both clustered dark matter and smoother dark energy and having a scale-dependent equation of state. This model predicts a relation between the ratio $r={\ensuremath{\rho}}_{V}/{\ensuremath{\rho}}_{\mathrm{DM}}$ of the energy densities of the two dark components and an expansion rate n of the universe [with $a(t)\ensuremath{\propto}{t}^{n}]$ in the form $n=(2/3)(1+r).$ For $r\ensuremath{\approx}2,$ we get $n\ensuremath{\approx}2$ which is consistent with observations.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/795c911227ca963569d7591db5fd5a887aeb63ab

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Structure formation in inhomogeneous dark energy models (2004, background): “Other authors (Padmanabhan 2002; Padmanabhan & Choudhury 2002; Bagla, Jassal & Padmanabhan 2003; Causse 2003) discussed more exotic models, based on tachyon fields, and argued that the equation of state is scaledependent.”
Gravity and the thermodynamics of horizons (2005, neutral): “[72,73].”
Dynamical systems applied to cosmology: Dark energy and modified gravity (2017, methodology): “21, this model can also be used as a dark matter unified theory, where both dark matter and dark energy are described by a single scalar field (Padmanabhan & Choudhury, 2002).”
Gravity and the Thermodynamics of Horizons (2003, background): “(This occurs in a wide class of dark energy models [72,73].”
Cosmological parameters from supernova observations: A critical comparison of three data sets (2003, background): “…& Ratra 1988; Ratra & Peebles 1988; Zlatev, Wang, & Steinhardt 1999) and the other corresponding to the tachyonic scalar fields (Padmanabhan 2002; Padmanabhan & Choudhury 2002; Frolov, Kofman, & Starobinsky 2002; Shiu & Wasserman 2002; Gibbons 2002; Fairbairn & Tytgat 2002; Mukohyama 2002;…”
Cluster number counts dependence on dark energy inhomogeneities and coupling to dark matter (2005, background): “In Padmanabhan & Choudhury (2002); Padmanabhan (2002); Bagla et al (2003) and Causse (2003) more exotic models, based on tachyon fields, have been discussed and they argued that the quintessence equation of state is scale– dependent.”