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Dénes Petz
Dénes Petz (1953–2018) was a Hungarian mathematical physicist and quantum information theorist. He is well known for his work on quantum entropy inequalities and equality conditions, quantum f-divergences, sufficiency in quantum statistical inference, quantum Fisher information, and the related concept of monotone metrics in quantum information geometry. He proposed the first quantum generalization of Rényi relative entropy and established its data processing inequality. He has written or coauthored several textbooks which have been widely read by experts in quantum information theory. He has also coauthored a book in the area of mathematical physics. Personal life He was born in Budapest, Hungary, on April 8, 1953. Education He received the M.Sc. degree in mathematics from the Eötvös Loránd University, Budapest, Hungary, in 1977 and the Ph.D. degree in mathematics from the Eötvös Loránd University, Budapest, Hungary, in 1979. In 1982, he received the qualificatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Budapest
Budapest is the Capital city, capital and List of cities and towns of Hungary, most populous city of Hungary. It is the List of cities in the European Union by population within city limits, tenth-largest city in the European Union by population within city limits and the List of cities and towns on the river Danube, second-largest city on the river Danube. The estimated population of the city in 2025 is 1,782,240. This includes the city's population and surrounding suburban areas, over a land area of about . Budapest, which is both a List of cities and towns of Hungary, city and Counties of Hungary, municipality, forms the centre of the Budapest metropolitan area, which has an area of and a population of 3,019,479. It is a primate city, constituting 33% of the population of Hungary. The history of Budapest began when an early Celts, Celtic settlement transformed into the Ancient Rome, Roman town of Aquincum, the capital of Pannonia Inferior, Lower Pannonia. The Hungarian p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Entropy
In physics, the von Neumann entropy, named after John von Neumann, is a measure of the statistical uncertainty within a description of a quantum system. It extends the concept of Gibbs entropy from classical statistical mechanics to quantum statistical mechanics, and it is the quantum counterpart of the Shannon entropy from classical information theory. For a quantum-mechanical system described by a density matrix , the von Neumann entropy is S = - \operatorname(\rho \ln \rho), where \operatorname denotes the trace and \operatorname denotes the matrix version of the natural logarithm. If the density matrix is written in a basis of its eigenvectors , 1\rangle, , 2\rangle, , 3\rangle, \dots as \rho = \sum_j \eta_j \left, j \right\rang \left\lang j \ , then the von Neumann entropy is merely S = -\sum_j \eta_j \ln \eta_j . In this form, ''S'' can be seen as the Shannon entropy of the eigenvalues, reinterpreted as probabilities. The von Neumann entropy and quantities based upon it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
