Time in Quantum Theory (TiQT) 2026

Session

Causality

26 May 2026, 09:00

Albano 3: 4204 - SU Conference Room (56 seats) (Albano Building 3)

40. TBD

Dr Vilasini Venkatesh (University of Grenoble Alpes)

26/05/2026, 09:00

Invited Talk

TBD

13. Identifying causal structures which cannot support quantum correlations without fine-tuning

Dr Shashaank Khanna (LIS, CNRS, Aix-Marseille University)

26/05/2026, 09:40

Talk

Bell’s eponymous theorem implies that Quantum Mechanics is incompatible with local causality. This leads to tension between Relativity and Quantum Theory because certain quantum correla- tions cannot be explained locally. Non-classicality of such quantum correlations is often realized to arise because of their non-local nature. Making use of the framework of classical causality and causal...

38. Higher-order processes beyond finite dimensional quantum theory

Dr Matt Wilson (CentraleSupelec, University of Paris-Saclay)

26/05/2026, 10:00

Talk

The framework of higher-order quantum operations (process matrices/supermaps) on finite-dimensional systems is primarily motivated by providing an information-theoretic abstraction of a spacetime environment. In doing so, it provides a way to extract operational causal structure from quantum circuit configurations, and a way to formalise quantum (indefinite) causal structures, which have been...

8. Exploring Sequential Identities within Indefinite Causal Structures

Mr Stanislav Filatov (University of Latvia)

26/05/2026, 11:00

Talk

This talk investigates an interpretation of the quantum switch by projecting its spatial paths into a superpositional basis. By redefining traditional operations as delocalized superpositional processes, we explore whether indefinite causal order can be recast as a definite sequential evolution through superposed identities. We specifically consider configurations where a particle might...

32. Closing the closed-labs loophole in device-independent tests of indefinite causality

Ms Hannah Seabrook (University of Bristol)

26/05/2026, 11:20

Talk

Device-independent (DI) tests draw conclusions about nature solely from observed correlations, without trusting the devices used. Originating in Bell's work on nonlocality, this paradigm has become central to foundational studies of quantum theory and practical applications (e.g., cryptography). More recently, DI tests of indefinite causal order (ICO) have extended this approach to more exotic...

31. Higher-order quantum processes respecting closed labs in a spacetime have quantum controlled causal order

Mr Matthias Salzger (International Centre for Theory of Quantum Technologies, University of Gdańsk)

26/05/2026, 11:40

Talk

In quantum causality and quantum information, there is a vast landscape of abstract quantum protocols that permit cyclic or non-acyclic causal structures between quantum operations. This includes widely studied frameworks for indefinite causal order and higher-order quantum processes, such as process matrices. However, a longstanding open question has been which is the largest class of such...

37. A Causal-Modelling Reconstruction of Quantum Mechanics

Mr Joppe Widstam (Max Planck Institute for the Physics of Complex Systems)

26/05/2026, 15:20

Talk

Using Bayes' theorem and the quantum formalism, one can infer unobserved variables from observed variables in a quantum experiment [1]. Quantum mechanics specifies the physical relations among these variables. These relations can be expressed as a joint probability distribution which can then be factorized into a causal model. Based on [2-3] we propose a simple causal model in which the...

34. Higher-order transformations of bidirectional quantum processes

Dr Kyrylo Simonov (University of Vienna)

26/05/2026, 15:40

Talk

Bidirectional devices are devices for which the roles of the input and output ports can be exchanged. Mathematically, these devices are described by bistochastic quantum channels, namely completely positive linear maps that are both trace-preserving and identity-preserving. Recently, it has been shown that bidirectional quantum devices can, in principle, be used in ways that are incompatible...