Despite decades of observation, the nature and origin of ultra-high energy
cosmic rays (UHECR), with energies in the EeV range and above, remains unknown.
The mere existence of UHECR implies that UHE neutrinos should also
be produced, but at a level that remains uncertain due to the relatively
poor knowledge of some key properties of the sources of UHECR. In the last few years,
the IceCube and Pierre Auger observatories have started to constrain
potential sources of UHECR through the non-observation of the so-called
cosmogenic neutrinos expected to be produced in interactions of UHECR
with the Cosmic Microwave Background. The low fluxes predicted in many
cosmogenic neutrino models motivate the need for a boost in sensitivity,
intended to be achieved with next-generation detectors exploiting the radio
technique in dense and dielectric media. Also, existing experiments are
planning to improve their performance by building larger and/or more precise
detectors. A summary of all these developments will be reported.