They’re still looking, but I do find it annoying that almost all papers on SETI are about how to search rather than on the search results.
http://arxiv.org/pdf/1505.05131.pdf The idea is that an adjanced civilisation might be utilising all the energy of pulsar jets as a power source. The idea works best for a pulsar where the jets are in the equatorial plane.
“Assuming the possibility of existence of a supercivilization we extend the idea of Freeman Dyson considering pulsars instead of stars. It is shown that instead of a spherical shell the supercivilization must use ring-like constructions. We have found that a size of the ”ring” should be of the order of (10^-4 – 10^-1)AU with temperature interval (300 – 600)K for relatively slowly rotating pulsars
The attempts to identify Dyson spheres on the sky were performed by several groups but no significant results were obtained. A couple of years ago Carrigan has published an article titled: ”IRAS-based whole sky upper limit on Dyson spheres”. This satellite covered almost 96% of the sky, implying that this is almost whole sky monitoring. According to the study, the searches have been conducted as for fully as for partially cloaked Dysion spheres. The search has revealed 16 Dyson sphere candidates.
In this manuscript we present a rather different idea how to search an advanced intelligence. In the framework of Dyson’s idea, the spherical shroud is constructed around stars. It is clear that in order to consume almost the total energy radiated by the star, it must be embedded inside a closed spherical shell, requiring enormous material to construct it. On the other hand, it is very well known that pulsars – rapidly rotating neutron stars – emit huge energy in narrow channels, therefore, if a supercivilization exists it can in principle utilize the energy of these objects. But in these cases, instead of sphere-like envelopes the super intelligence has to use ring-like structures around the pulsars.”
