56 citations · 340 across the 24 of their papers we have counts for
16 papers · 1 filter
Causality from the spectrum: Emergence of causal order from process-matrix mereology
Varun Kushwaha, Nicolas Loizeau, Alexei Grinbaum +1
In Hamiltonian systems, the only basis-independent quantity is the spectrum. Given a spectrum, quantum mereology seeks preferred tensor-product decompositions into local subsystems…
Frame perspectives for process matrices: from coordinate parametrization to spacetime representation
Luca Apadula, Alexei Grinbaum, Časlav Brukner
We study how to implement and transform frame perspectives for quantum processes in the process-matrix formalism. We argue that, for pure processes, the causal reference frames (CR…
Agency under indefinite causality: operational eternalism in higher-order quantum theory
Alexei Grinbaum
After two decades of research on indefinite causality, a conceptual lesson emerges: the tension between operational quantum theory and dynamical spacetime physics requires observer…
Anomalous non-classicality via correlative and entropic Bell inequalities
Sabiha Durucan, Alexei Grinbaum
Entropic Bell inequalities witness contextual probability distributions on sets of jointly measurable observables. We find that their violation does not entail a violation of the c…
Channel capacity enhancement with indefinite causal order
Nicolas Loizeau, Alexei Grinbaum
Classical communication capacity of a channel can be enhanced either through a device called a 'quantum switch' or by putting the channel in a quantum superposition. The gains in t…
How device-independent approaches change the meaning of physical theory
Alexei Grinbaum
Dirac sought an interpretation of mathematical formalism in terms of physical entities and Einstein insisted that physics should describe "the real states of the real systems". Whi…