Cosmic explosions, life in the Universe and the Cosmological Constant

Abstract

Galactic Gamma-Ray Bursts (GRBs) are copious sources of gamma-rays that can pose a threat to complex life. Using recent determinations of their rate and the probability of GRBs causing massive extinction, we explore what type of universes are most likely to harbour advanced forms of life. For this purpose we use cosmological N-body simulations to determine at what time and for what value of the cosmological constant ($\Lambda$) the chances of life being unaffected by cosmic explosions are maximised. We find that $\Lambda -$dominated universes favour the survival of life against GRBs. Within a $\Lambda$CDM cosmology, the parameters that govern the likelihood of life survival to GRBs are dictated by the value of $\Lambda$ and the age of the Universe. We find that we seem to live in a favorable point in this parameter phase space which minimises the exposure to cosmic explosions, yet maximises the number of main sequence (hydrogen-burning) stars around which advanced life forms can exist.

Accepted version in Physical Review Letters

References in corpus (7)

• The Galaxy Population Hosting Gamma-Ray Bursts
• The star formation histories of galaxies in the Sloan Digital Sky Survey
• Astrophysical Ionizing Radiation and the Earth: A Brief Review and Census of Intermittent Intense Sources
• On the role of GRBs on life extinction in the Universe
• Testing anthropic predictions for Lambda and the CMB temperature
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• The Size Distribution of Inhabited Planets

Cited by in corpus (8)

• The Degree of Fine-Tuning in our Universe -- and Others
• Galaxy Formation Efficiency and the Multiverse Explanation of the Cosmological Constant with EAGLE Simulations
• Multiverse Predictions for Habitability: Fraction of Life that Develops Intelligence
• Dark energy from the motions of neutrinos
• 4-volume cutoff measure of the multiverse
• Lethal radiation from nearby supernovae helps to explain the small cosmological constant
• Gamma Ray Bursts: Not so Much Deadlier than We Thought
• Life in a random universe: Sciama's argument reconsidered