activity
20242026
collaborators

7 papers

quant-ph2026

Entanglement Generation Beyond Quantum Theory: From Product States to Popescu-Rohrlich Boxes

Shun Umekawa, Akihiro Hokkyo, Hayato Arai +1

Entanglement generation is a fundamental dynamical capability in quantum information science and underpins many quantum advantages. While quantum theory enables it through unitary…

quant-ph2026

Intersubjectivity as a principle determining physical observables and non-classicality

Shun Umekawa, Koki Ono, Hayato Arai

We identify an operational principle that singles out Projection-Valued Measures (PVMs) among general Positive Operator-Valued Measures (POVMs), bridging the modern quantum measure…

math.AG2025

Autoequivalences and stability conditions on a degenerate K3 surface

Hayato Arai

We study autoequivalences and stability conditions on the derived category of coherent sheaves on a singular surface which arises as an open subvariety of a type III Kulikov de…

math.AG2025

Half-spherical twists on derived categories of coherent sheaves

Hayato Arai

For a flat morphism between smooth quasi-projective varieties and its fiber , we prove that spherical objects on pushed-forward from ind…

quant-ph2025

Hypothesis testing and Stein's lemma in general probability theories with Euclidean Jordan algebra and its quantum realization

Kanta Sonoda, Hayato Arai, Masahito Hayashi

Even though quantum information theory gives advantage over classical information theory, these two information theories have a structural similarity that many exponet rates of inf…

quant-ph2025

Quantum Implementation of Non-Positive-Operator-Valued Measurements in General Probabilistic Theories by Post-Selected POVMs

Hayato Arai, Masahito Hayashi

It is important problem to clarify the class of implementable quantum measurements from both fundamental and applicable viewpoints. Positive-Operator-Valued Measure (POVM) measurem…