<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:14pt"><div><span><font size="2" face="Arial">scerir wrote"</font></span></div><div><span></span> </div><div><span>> Faster-than-c signals, special relativity, and causality<br>> <a href="http://arxiv.org/abs/gr-qc/0107091" target="_blank"><font color="#234786">http://arxiv.org/abs/gr-qc/0107091</font></a><br>>Stefano Liberati, Sebastiano Sonego, Matt Visser</span></div><div><span><br>>Abstract: Motivated by the recent attention on superluminal phenomena, we investigate<br>> the compatibility between faster-than-c propagation and the fundamental principles of<br>> relativity and causality. We first argue that special relativity can easily accommodate --<br>> indeed, does not exclude -- faster-than-c signalling at the kinematical level. As far as<br>> causality is concerned, it is impossible to make
statements of general validity, without<br>> specifying at least some features of the tachyonic propagation. We thus focus on the<br>> Scharnhorst effect (faster-than-c photon propagation in the Casimir vacuum), which is<br>> perhaps the most plausible candidate for a physically sound realization of these<br>> phenomena. We demonstrate that in this case the faster-than-c aspects are 'benign' and<br>> constrained in such a manner as to not automatically lead to causality violations.</span></div><div><br>The orthodox view could be that neutrinos are traveling at true vacuum speed because</div><div>they do not interact with the E&M portions of vacuum in the same manner that photons</div><div>do.</div><div> </div><div>Dennis May</div></div></body></html>