GRB Physics for Competitions Vol 2 PDF is a valuable resource for students preparing for physics competitions. The book provides:
One of the most common pitfalls in GRB problems is mixing up the Doppler factor for the prompt emission (( \delta_D = [\Gamma(1-\beta\cos\theta)]^-1 )) versus the afterglow. The new PDF: grb physics for competitions vol 2 pdf upd better
But competitors quickly hit a wall. Real IOAA problems involve: GRB Physics for Competitions Vol 2 PDF is
Standard: (\delta t_\textobs = \fracR2\Gamma^2 c (1+z) \Rightarrow \Gamma = \sqrt \fracR (1+z)2 c \delta t_\textobs ). Assume (R \sim c \times t_\textengine) but minimal (R) = ( c \times) (engine timescale) ≈ (c \times) break? Simpler: Use (\Gamma > \sqrt \fracc T2 \delta t_\textobs ) with (T) not given. Actually : $\Gamma > \sqrt \frac1+z2 \fracT\delta t $ but typical competition gives $T$ from light curve envelope. Without $T$, use: Minimum possible (R \sim 2\Gamma^2 c \delta t/(1+z)) must be > (R_g) of black hole? No — better: Use known relation : (\Gamma > 100 \left( \frac0.01\texts\delta t \frac1+z2 \right)^1/2) — plug $z=1,\delta t=0.01$: (\Gamma > 100). (This is standard lower limit). Real IOAA problems involve: Standard: (\delta t_\textobs =