The quantum field theory framework needed some adjustment for Borinsky and Vogtmann to get the right count. For instance, in quantum field theory, two graphs that are mirror images of each other are ...

Physicists have algorithms to compute the probabilities of no-loop and one-loop scenarios, but many two-loop collisions bring computers to their knees. This imposes a ceiling on predictive precision — ...

In loop quantum gravity there is no such thing as space – only fields. In “Loop quantum gravity” Carlo Rovelli explains how he arrived at a background-independent quantum field theory by treating the ...

Quantum field theory marries the ideas of other quantum theories to depict all particles as “excitations” that arise in underlying fields. The British physicist Paul Dirac started the ball ...

However, research on loop quantum cosmology offers a possible solution. It suggests that gravity, in effect, becomes repulsive. Consequently, loop quantum cosmology predicts that our present universe ...

These are the instructions used to calculate how particles interact in quantum field theory. They examined the renormalizability of the theory at one-loop order—the first level of quantum ...

Quantum mechanics is the study of atomic and subatomic particles at normal speeds, while quantum field theory is the study of those same particles at relativistic speeds.

In loop quantum gravity, or LQG, space-time is a network. The smooth background of Einstein’s theory of gravity is replaced by nodes and links to which quantum properties are assigned.

When it comes to the question of a quantum theory of gravity, it's often said that string theory is the only game in town. These four alternatives might cause a rethink of that.