6 papers
Indefinite Causal Order Reverses the Real-Complex Hierarchy
Jacopo Surace, Shintaro Minagawa, Ravi Kunjwal
[Note added after submission. After posting the first version of this preprint and corresponding with Ved Kunte and Kuntal Sengupta, we identified an issue with the claimed separat…
Generalizing Bell nonlocality without global causal assumptions
Ravi Kunjwal, Ognyan Oreshkov
Bell scenarios are multipartite scenarios that exclude any communication between parties. This constraint leads to a strict hierarchy of correlation sets in such scenarios, namely,…
All star-incompatible measurements can certify steering-based randomness
Shintaro Minagawa, Ravi Kunjwal
Certifying that quantum randomness generated by untrusted devices is unpredictable to an attacker (say, Eve) is crucial for device-independent security. Bipartite protocols where o…
Paradox-free classical non-causality and unambiguous non-locality without entanglement are equivalent
Hippolyte Dourdent, Kyrylo Simonov, Andreas Leitherer +5
Closed timelike curves (CTCs) challenge our conception of causality by allowing information to loop back into its own past. Any consistent description of such scenarios must avoid…
Quantumness via Discrete Structures
Ravi Kunjwal
Quantum theory departs from classical probabilistic theories in foundational ways. These departures--termed quantumness here--power quantum information and computation. This thesis…
No-go theorem for quantum realization of extremal correlations
Sujan V. K, Ravi Kunjwal
The study of quantum correlations is central to quantum information and foundations. The paradigmatic case of Bell scenarios considers product measurements implemented on a multipa…