Gamma-Ray Burst Light Curve Reconstruction: A Comparative Machine and Deep Learning Analysis
A. Manchanda, A. Kaushal, M. G. Dainotti, A. Deepu, S. Naqi, J. Felix, N. Indoriya, S. P. Magesh, H. Gupta, K. Gupta, A. Madhan, D. H. Hartmann, A. Pollo, M. Bogdan, J. X. Prochaska, N. Fraija, D. Debnath
TL;DR
This work tackles gaps in gamma-ray burst afterglow light curves by comparing nine machine-learning and statistical approaches against the Willingale model on a large, diverse 521-GRB dataset. It demonstrates that the MLP achieves the best 5-fold CV MSE ($\approx0.0275$) while substantially reducing plateau-parameter uncertainties; the Attention U-Net yields the strongest reduction in $T_a$, $F_a$, and $\alpha$ uncertainties albeit with higher CV error. The results emphasize a trade-off between reconstruction accuracy and uncertainty control, with MLP offering a robust baseline and Attention U-Net excelling at suppressing outliers. These improvements enhance the utility of GRBs as standard candles and cosmological probes, and the framework lays groundwork for extending LC reconstruction to multi-wavelength data and future missions.
Abstract
Gamma-Ray Bursts (GRBs), observed at high-z, are probes of the evolution of the Universe and can be used as cosmological tools. Thus, we need correlations with small dispersion among key parameters. To reduce such a dispersion, we mitigate gaps in light curves (LCs), including the plateau region, key to building the two-dimensional Dainotti relation between the end time of plateau emission (Ta) and its luminosity (La). We reconstruct LCs using nine models: Multi-Layer Perceptron (MLP), Bi-Mamba, Fourier Transform, Gaussian Process-Random Forest Hybrid (GP-RF), Bidirectional Long Short-Term Memory (Bi-LSTM), Conditional GAN (CGAN), SARIMAX-based Kalman filter, Kolmogorov-Arnold Networks (KANs), and Attention U-Net. These methods are compared to the Willingale model (W07) over a sample of 521 GRBs. MLP and Attention U-Net outperform other methods, with MLP reducing the plateau parameter uncertainties by 37.2% for log Ta, 38.0% for log Fa, and 41.2% for alpha (the post-plateau slope in the W07 model), achieving the lowest 5-fold cross-validation (CV) mean squared error (MSE) of 0.0275. Attention U-Net achieved the lowest uncertainty of parameters, a 37.9% reduction in log Ta, a 38.5% reduction in log Fa and a 41.4% reduction in alpha, but with a higher MSE of 0.134. Although Attention U-Net achieves the largest uncertainty reduction, the MLP attains the lowest test MSE while maintaining comparable uncertainty performance, making it the more reliable model. The other methods yield MSE values ranging from 0.0339 to 0.174. These improvements in parameter precision are needed to use GRBs as standard candles, investigate theoretical models, and predict GRB redshifts through machine learning.
