String theory

Pushed down to a certain scale, the laws of physics seem to fall apart. Astrid Eichhorn, a leader in an area of study called asymptotic safety, thinks we just need to push a little further.

In an unprecedented step, researchers crafted a detailed model compatible with the universe’s accelerated expansion.

Years ago, an audacious Fields medalist outlined a sweeping program that, he claimed, could be used to resolve a major problem in algebraic geometry. Other mathematicians had their doubts. Now he says he has a proof.

Promise and controversy continues to surround string theory as a potential unified theory of everything. In the latest episode of The Joy of Why, Cumrun Vafa discusses his progress in trying to find good, testable models hidden among the ‘swampland’ of impossible universes.

Using machine learning, string theorists are finally showing how microscopic configurations of extra dimensions translate into sets of elementary particles — though not yet those of our universe.

An idea derived from string theory suggests that dark matter is hiding in a (relatively) large extra dimension. The theory makes testable predictions that physicists are investigating now.

Eugenio Calabi, who died on September 25, conceived of novel geometric objects that later became fundamental to string theory.

Even empty space bubbles with energy, according to quantum mechanics — and that fact affects almost every facet of physical reality. The theoretical physicist Isabel Garcia Garcia explains to Steven Strogatz why it’s so important in modern physics to understand what a true vacuum is.

The key to understanding the origin and fate of the universe may be a more complete understanding of the vacuum.