Yitang Zhang

Riemann Hypothesis: What Yitang Zhang’s New Paper Means and Why You Should Care

An Ulam spiral of the number of divisors of the first 100,000 natural numbers. Numbers with exactly two divisors – 1 and the number itself – are called prime numbers. Credit: Cortexd/Wikimedia Commons, CC BY-SA 3.0

Review: the Trials and Delights on the Long Road to the Twin Prime Conjecture