DSR transformations with zero time delay

TL;DR

This paper derives DSR transformations with zero time delay at first order in Planck length, showing some DSR theories mimic special relativity and emphasizing the importance of considering all quantum gravity effects collectively.

Contribution

It presents the first-order DSR transformations with zero time delay, revealing that some DSR theories behave like special relativity in this approximation.

Findings

Zero time delay transformations are derived in DSR theories.

Some DSR theories can mimic special relativity at first order.

Quantum gravity effects should be considered collectively in observations.

Abstract

In doubly special relativity (DSR) theories the speed of the light usually depends on the frequency. Thus, we expect that light from very distant stars and gamma ray bursts have additional time delays with respect to special relativity. In this paper, we will find the general DSR transformations in the first order of the Planck length which have zero time delay. With respect to these transformations zero time delay isn't only a consequence of special relativity, and we can find some DSR theories which behave like special relativity in the first order of the Planck length in some aspects. We notify that for a correct conclusion in the observations of the quantum gravity effects we should look to all quantum gravity effects together and not one.