Virtual Seminar Series
Jasper van Wezel, University of Amsterdam.
- Time
- 12pm - 1pm
- Date
- 11 Mar 2026
- Duration
- 1 hour(s)
- Location
- Online
More information
- Presenters
Jasper van Wezel,
University of Amsterdam.- Audience
- All Action members
- Registration Required
- No
The STOCHASTICA SNIP seminar will be held online every two weeks starting on January 14. Talks of 30-45 minutes will be followed by 15-30 minutes of open discussion. Initially, seminars will be focused on introducing new problems and applications, to stimulate further discussions and ideas within individual working groups.
The fourth seminar was given by Prof Jasper van Wezel (University of Amsterdam), and chaired by Prof Sonja Cox, (Leader, Working Group 2). Note the unusual time of 12pm Ireland time.
The stochastic evolution of quantum measurement
Despite the fact that quantum physics gives incredibly accurate predictions for the dynamics of microscopic particles, it is unable to explain the observed behaviour of measurement machines built out of many such particles. This measurement problem remains one of the major foundational problems of modern
physics, affecting our understanding of phase transitions, thermodynamics, nuclear physics, cosmology, and other areas involved with the quantum-classical crossover.
One class of approaches in trying to solve the measurement problem, revolves around the assumption that Schrödinger's equation, like all equations in physics, is only an approximation to the exact laws of nature. Small modifications to Schrödinger’s time evolution may then be proposed that have no noticeable effect on the microscopic scale of elementary particles, but which dominate the dynamics in the macroscopic regime. To describe the observed properties of quantum measurements, such modifications necessarily appear in the form of stochastic differential equations.
In this seminar, I will give an overview of some recent attempts to construct an equation describing stochastic quantum evolution. I will emphasise the mathematical consequences of possible physical assumptions. These highlight how the present approach, based on so-called spontaneous symmetry breaking, differs from previous proposals. They also reveal the inherent difficulties in identifying any set of stochastic differential equations that faithfully reproduces all observed aspects of quantum measurement, and I will discuss recent attempts to overcome some of these.