In this talk I will discuss how modelling local, nonperturbative measurements in relativistic field theories has traditionally led to a choice between mathematical intractability and frictions with covariance and causality.

The recent development of technologies based on fundamental quantum physical phenomena such as superposition and entanglement adds new weight to the question whether nature may have found similar solutions.

Contextuality is a key distinguishing feature between classical and quantum physics. It expresses a fundamental obstruction to describing quantum theory using classical concepts. In turn, when understood as a resource for quantum computation, it is…

The concept of a "quantum reference frame" has been explored by physicists and philosophers working together as a way to make sense of the idea of quantum superpositions of space-times.

Einstein's general theory of relativity is based on the principle of equivalence - in essence, dating back to Galileo - which asserts that, locally, the effect of a gravitational field is equivalent to that of an accelerating reference frame, so that…

The setup of the Einstein-Podolsky-Rosen (EPR) paradox leads to an observer-dependent description of the quantum state from the perspective of quantum information theory.

In Yang-Mills gauge theory on a Cauchy surface the group of physical gauge symmetries carrying direct empirical significance (DES) is often believed to equal a quotient of the group of boundary-preserving gauge symmetries by its subgroup of…

I will present the effects of changes in internal energy on gravity-induced entanglement in interference experiments, which in principle allows for faster-than-light communication.