Study: Self-replicating alien space probes in our solar system?

” A group of researchers from Edinburgh University have said that based solely on the age of the universe and feasible interstellar flight technology, “self replicating” probes from alien civilizations could already have arrived in our solar system.

   According to mathematicians Arwen Nicholson and Duncan Forgan, in a paper entitled “Slingshot Dynamics for Self Replicating Probes and the Effect on Exploration Timescales,” published on July 5, 2013, in the journal Astrobiology, alien space probes propelled to the vicinity of our Sun using the gravitational field of stars rather than of planets, as humans have accomplished with the Voyager space probes, could already be in our solar system, but it could be that we are unable to detect them.”