particle

Black holes snacking on small stars create particle accelerators that bombard Earth with cosmic rays

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a bright orb next to a cloud of brown dust

Using 16 years of data from NASA’s gamma-ray detecting Fermi spacecraft, astronomers have discovered that “microquasars,” systems in which a black hole is slowly devouring a star, may be small, but they pack one heck of a punch. Despite their diminutive nature, this research suggests even microquasars snacking on small stars can have an impressive … Read more

Digital quantum simulation of cosmological particle creation with IBM quantum computers

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We will follow the toy model provided in Ref.22. The infinitesimal line element ds, whose coefficients determine the metric of the spacetime, in a Friedman–Lemaitre–Robertson–Walker universe is given by Refs.23,24,25,26,27,28,29: $$\begin{aligned} ds^2=dt^2-a^2(t)dx^2, \end{aligned}$$ (1) where a(t) is the scale factor, which only depends on time. We can make a change of variables to conformal time, … Read more