Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Is there any evidence for extra-dimensions or quantum gravity effects
  from the delayed MeV-GeV photons in GRB 940217?   The discovery of X-ray afterglows of GRBs, and the identification of host
galaxies of GRBs, confirm the cosmological origin of GRBs. However, the
discovery of the delayed MeV-GeV photons in GRB940217 imposes serious
challenges for the standard emission model of GRB. Although the delayed MeV-GeV
photons might be explained by some radiation emission mechanisms, the mystery
of detecting an 18 GeV photon still remains unsolved. We suggest that the
detection of the 18-GeV photon $ \sim $4500 s after the keV/MeV burst in GRB
940217 provides a strong evidence for the existence of extra-dimensions and/or
quantum gravity effects. The delay scale of the 18-GeV photon leads to an
estimation of the fundamental energy scale, associated with the linear energy
dependence of the speed of light, of the order of $2.1\times 10^{15}$ GeV,
which is consistent with the results obtained by another independent analysis
on the data of OSSE and BATSE.

37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
19
The categories of this paper are: eess
3
The categories of this paper are: physics
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
16
The categories of this paper are: stat