Ordinal Research Institute

Supporting collaboration to answer fundamental questions in theoretical physics and beyond

Latest Paper

Incorporating Gravity into the Path Integral of Quantum Mechanics Using the Thermodynamics of Spacetime

Garrett Biehle, Clifford Ellgen, Bassem Sabra, & Sebastian Zając

We use principles from the thermodynamics of spacetime to modify the path integral of quantum mechanics. Entropy of the vacuum is interpreted as microstates that correspond to the measure of the path integral. The result is a contribution to the action that is proportional to the Einstein-Hilbert action. Because the contribution is real, not imaginary, it is unlikely to cause convergence problems. Paths that minimize the Einstein-Hilbert action make the largest contribution to the path integral, implying that the maximum likelihood paths are solutions of the Einstein equation.

Preprint not yet submitted for publication

Recent Events

Tuesday, May 17, 2022

Branes and Quantized Fields: Towards Quantum Gravity within Braneworld Scenarios

Matej Pavšič, Jožef Stefan Institute

In braneworld scenarios, spacetime is considered as a brane embedded in a higher-dimensional space. Quantization of the Dirac-Nambu-Goto (DNG) brane is a tough problem. We will show how to solve it by considering a brane as a “point-particle” in an infinite-dimensional brane space, whose metric is dynamical, just like in general relativity. Such a brane theory, amongst others, includes the flat brane space, whose metric is the infinite-dimensional analog of the Minkowski space metric. A brane living in the latter space, the so-called “flat brane”,  is like a bunch of non-interacting point particles. Quantization of the latter system leads to a system of non-interacting quantum fields. Interactions can be included if we consider a nontrivial metric in the space of fields. Then the effective classical brane is no longer flat. For a particular choice of metric in the field space, we obtain the DNG brane. Finally, the role of a generic multi-dimensional configuration space of matter and its relation to spacetime will be considered.