# Erica Klarreich

## Mathematicians Report New Discovery About the Dodecahedron

Three mathematicians have resolved a fundamental question about straight paths on the 12-sided Platonic solid.

## In a Single Measure, Invariants Capture the Essence of Math Objects

To distinguish between fundamentally different objects, mathematicians turn to invariants that encode the objects’ essential features.

## The Infinite Primes and Museum Guard Proofs, Explained

A simple, step-by-step breakdown of two “perfect” math proofs.

## Graph Isomorphism Vanquished—Again

László Babai has fixed the flaw in his retracted claim.

## Complexity Theory Problem Strikes Back

The legendary graph isomorphism problem may be harder than a 2015 result seemed to suggest.

## All Is Not Fair in Cake-Cutting and Math

When divvying something up, there's more than one way to define what's fair.