Astrophys Space Sci (2015) 357:118 DOI 10.1007/s10509-015-2346-z ORIGINAL ARTICLE Magnetized anisotropic ghost dark energy cosmological model Kanika Das 1 · Tazmin Sultana 1 Received: 6 January 2015 / Accepted: 7 April 2015 / Published online: 13 May 2015 © Springer Science+Business Media Dordrecht 2015 Abstract We present in this paper a LRS Bianchi type I cosmological model with dark matter and anisotropic ghost dark energy in presence of magnetic field. We have solved the Einstein’s field equations with a particular form of Hub- ble parameter. The physical and geometrical behaviors of the model are discussed. It is observed that the anisotropy of the universe and that of the ghost dark energy tends to zero at late times and the universe becomes spatially homogeneous, isotropic and flat. The coincidence parameter increases with time. We have also studied the statefinder parameters. The results obtained are in agreement with the recent days ob- servations. Keywords LRS Bianchi type-I space time · Anisotropic ghost dark energy · Magnetic field · Coincidence parameter · Statefinder parameter 1 Introduction Recently, there are sufficient observational evidences which trigger at the fact that our universe is experiencing a phase of acceleration. There exists an exotic form of energy with neg- ative pressure and positive energy density which is respon- sible for the accelerating expansion of the universe. This is referred to as dark energy. Observational evidences of the dark energy such as CMBR (Cadwell and Doran 2004), type Ia supernovae (Permutter et al. 1999), galaxy redshift surveys (Fedeli et al. 2009), large scale structure (Koivisto B K. Das daskanika2@gmail.com T. Sultana tazmingu@gmail.com 1 Department of Mathematics, Gauhati University, Assam, India et al. 2008; Daniel 2008) can be mentioned. The first and simple candidate for dark energy is the cosmological con- stant (Weinberg 1989) with the equation of state ω equal to −1. But there are problems with cosmological constant. It suffers the fine-tuning and cosmic coincidence problem (Copeland et al. 2006). Researchers have proposed a va- riety of some other models to explain the nature of dark energy such as quintessence with EoS ω> −1 (Barreiro et al. 2000), phantom with EoS ω< −1 (Caldwell 2002), k-essence (Armendariz-Picon et al. 2001), tachyon (Bagla et al. 2003), Chaplygin gas (Bento et al. 2002 and 2003), holographic dark energy (Li 2004) and so on. Recently, it is very interesting to study another type of dark energy called ghost dark energy (GDE). A new model of dark energy called Veneziano ghost dark energy has been recently proposed (Urban and Zhitnitsky 2010; Ohta 2011; Cai et al. 2011). The U(1) problem in low- energy effective theory can be explained by Veneziano ghost field. The ghost field has no contribution to the vacuum energy density in Minkowski space-time, but in a curved space-time, it contributes to the vacuum energy density proportional to  3 QCD H (Zhitnitsky 2010; Holdom 2011; Zhitnitsky 2011) where  QCD is QCD mass scale and H is the Hubble parameter. The newly constructed ghost dark energy model is free from the fine tuning and cosmic co- incidence problems. For the ghost dark energy the energy density is given by the relation ρ G = τH (Ohta 2011), where τ is a constant with dimension [energy]. 3 Later a generalized model (Cai et al. 2012) has been introduced as ρ G = τH + ηH 2 with η as a constant parameter. Khur- shudyan and Khurshudyan (2014) have investigated the in- teracting varying ghost dark energy models. Cosmic microwave background radiation (CMBR) (Mis- ner 1968) is in favor of the existence of the anisotropic phase of the universe which in later times becomes isotropic.