Deviation From \Lambda CDM With Cosmic Strings Networks
  In this work, we consider a network of cosmic strings to explain possible deviation from \Lambda CDM behaviour. We use different observational data to constrain the model and show that a small but non zero contribution from the string network is allowed by the observational data which can result in a reasonable departure from \Lambda CDM evolution. But by calculating the Bayesian Evidence, we show that the present data still strongly favour the concordance \Lambda CDM model irrespective of the choice of the prior. 
Sumit Kumar, Akhilesh Nautiyal and Anjan A. Sen
astro-ph.CO gr-qc