skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • Home
  • Search Results
  • Page 1 of 1

Search for: All records

Creators/Authors contains: "Gavassino, L."

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. ; ; (, Physical Review D)
  2. ; ; (, Physical Review Letters)
  3. ; ; (, Physical Review Letters)
    We show that linear superpositions of plane waves involving a single-valued, covariantly stable dispersion relation $$\omega(k)$$ always propagate outside the lightcone, unless $$\omega(k) =a+b k$$. This implies that there is no notion of causality for individual dispersion relations, since no mathematical condition on the function $$\omega(k)$$ (such as the front velocity or the asymptotic group velocity conditions) can serve as a sufficient condition for subluminal propagation in dispersive media. Instead, causality can only emerge from a careful cancellation that occurs when one superimposes all the excitation branches of a physical model. This is shown to happen automatically in local theories of matter that are covariantly stable. 
    more » « less
    Full Text Available 
  4. ; ; (, Physical Review D)
  5. ; (, Physical Review A)
    Full Text Available