Speaker
Description
We present a new analysis of cosmic dipole anisotropy using gamma-ray bursts (GRBs) as high-redshift standardizable candles. GRBs are ideal probes for testing the cosmological principle thanks to their high luminosity, wide redshift range, and nearly isotropic sky coverage. For the first time, we employ the luminosity-time (L-T) relation, corrected for redshift evolution, to standardize a sample of 176 long GRBs detected by Swift. We test for dipolar modulations using both the Dipole Fit Method and a new approach, the Anisotropic Residual Analysis Method. Both methods yield consistent results, with a statistically significant dipole signal, which will be discussed in the talk. We also show how, by incorporating a dipole term, residual correlations are eliminated, showing that the dipole model provides a better fit than standard isotropic ΛCDM.