A new physics paper takes a step toward creating a long-sought "theory of everything" by uniting gravity with the quantum world. However, the new theory remains far from being proven observationally.

a) Diagram of the quantum circuit ... a test particle following a CTC can interact with its former self in the past. A widely accepted quantum theory of CTCs was proposed by Deutsch. Here we analyze ...

It's not quite a theory of quantum gravity ... happen through the gravitational field." A diagram demonstrating the flat space-time of the quantum field and the curved field expected for ...

(Phys.org)—Although there are many counterintuitive ideas in quantum theory, the idea that influences can travel backwards in time (from the future to the past) is generally not one of them.

Quantum electrodynamics (QED) is the unified “electroweak” theory of electromagnetism and the weak nuclear force, which governs nuclear processes such as radioactive beta decays that are ...