42,772 articles
Hyman Bass
Hyman Bass (born 1932) is an American mathematician who founded algebraic K-theory and later studied the mathematical knowledge teachers need, winning the National Medal of Science in 2007.
HyMeX
HyMeX, the Hydrological Cycle in the Mediterranean Experiment, was a 10-year international research program from 2010 to 2020 studying the Mediterranean water cycle, especially heavy precipitation, flash floods, and droughts.
Hyo Jae Yoon
Hyo Jae Yoon (윤효재) is a South Korean chemist and professor at Korea University in Seoul, known for a 2010 Science paper on supramolecular catalysts and for molecular thermoelectricity.
Hyotcherl Ihee
Hyotcherl Ihee (이효철) is a South Korean chemist, a KAIST professor since 2003 and founding director of the IBS Center for Advanced Reaction Dynamics, known for time-resolved X-ray liquidography.
Hyoyoung Lee
Hyoyoung Lee is a South Korean materials chemist, professor at Sungkyunkwan University and Associate Director of the IBS Center for Integrated Nanostructure Physics, known for graphene materials and single-atom electrocatalysis.
Hypatia
Hypatia of Alexandria, daughter of the mathematician Theon, was a Greek mathematician, astronomer, and philosopher, the first woman in the history of mathematics, murdered by a mob in 415.
HYPE (hydrological model)
HYPE (HYdrological Predictions for the Environment) is a semi-distributed catchment model simulating water flow and nutrients, developed at SMHI in Sweden and applied operationally there since 2008.
Hyper Rayleigh scattering spectroscopy
Hyper Rayleigh scattering spectroscopy is a nonlinear optical technique that measures incoherent second-harmonic light from molecules in solution to determine their first hyperpolarizability, introduced by Clays and Persoons in 1991.
Hyper Suprime-Cam
Hyper Suprime-Cam (HSC) is an 870-megapixel optical imaging camera at the prime focus of the 8.2 m Subaru Telescope on Maunakea, Hawaii, used for wide-field surveys.
Hyper Suprime-Cam Subaru Strategic Program
The Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) is a three-layer optical imaging survey on the Subaru Telescope in Hawaii, begun in 2014 to study dark matter and dark energy.
Hyper-Kamiokande (ハイパーカミオカンデ)
Hyper-Kamiokande (ハイパーカミオカンデ) is a next-generation underground neutrino detector under construction in Hida, Japan, by the University of Tokyo and KEK, aiming to start observation in 2028.
Hyperarithmetic theory
Hyperarithmetic theory is a branch of computability theory introduced in the early 1950s by Davis, Mostowski, and Kleene, characterizing the hyperarithmetical sets via definability and iterated Turing jumps.
Hyperarithmetical theory
Hyperarithmetical theory, which studies the hyperarithmetic sets, or HYP, is the branch of computability theory that iterates the Turing jump through the computable ordinals, a hierarchy begun by Stephen Cole Kleene in the 1950s.
Hyperbola
A hyperbola is a conic section with two open, mirror-image branches, defined by a constant difference of distances to two foci, named by Apollonius of Perga.
Hyperbolic 3-manifold
A hyperbolic 3-manifold is a three-dimensional manifold with a complete Riemannian metric of constant negative curvature, the central object of William Thurston's 1980s geometrization program in topology.
Hyperbolic functions
The hyperbolic functions, also called hyperbolic trigonometric functions, are elementary functions built from exponentials that play the role for the hyperbola that sine and cosine play for the circle, describing hanging cables and rapidity in relativity.
Hyperbolic geometry
Hyperbolic geometry, also called Lobachevsky geometry, is a non-Euclidean geometry with constant negative curvature in which triangles have angle sums below 180°, discovered independently by Lobachevsky and Bolyai in the 1820s.
Hyperbolic group
A hyperbolic group, also called a word-hyperbolic group, is a finitely generated group whose Cayley graph with the word metric is hyperbolic, meaning geodesic triangles are uniformly thin; introduced by Mikhail Gromov in 1987.
Hyperbolic lattices
Hyperbolic lattices are regular tessellations of the two-dimensional hyperbolic plane, a non-Euclidean space of uniform negative curvature, used as synthetic platforms for band theory, topology, and disorder physics.
Hyperbolic manifold
A hyperbolic manifold is a Riemannian manifold locally isometric to hyperbolic space of constant curvature -1, playing a central role in 3-dimensional topology and geometrization.
Hyperbolic metamaterial
A hyperbolic metamaterial is an artificial uniaxial optical material with opposite-sign permittivity components, giving an open hyperboloid dispersion that supports high-k waves for sub-diffraction imaging.
Hyperbolic metasurfaces
Hyperbolic metasurfaces are two-dimensional, subwavelength-structured surfaces whose surface plasmon polaritons have hyperbolic dispersion, enabling strong light confinement, negative refraction, and applications in imaging, emission control, and on-chip optics.
Hyperbolic motion (relativity)
Hyperbolic motion in relativity is the rectilinear motion of a body whose constant proper acceleration gives it a hyperbolic worldline, first studied by Max Born and underlying the Rindler horizon.
Hyperbolic paraboloid
A hyperbolic paraboloid is a saddle-shaped quadric surface, one of only two doubly ruled surfaces in three-dimensional space, with two families of straight lines lying entirely on it.
Hyperbolic phonon polaritons
Hyperbolic phonon polaritons are quasiparticles formed when infrared photons couple to lattice vibrations in polar crystals, confining light to scales far below its free-space wavelength with low loss.
Hyperbolic phonon polaritons in hexagonal boron nitride
Hyperbolic phonon polaritons in hexagonal boron nitride (HPhPs) are hybrid light-matter quasiparticles formed when infrared photons couple to optical phonons in the layered crystal hexagonal boron nitride.
Hyperbolic plane
The hyperbolic plane is the unique complete, simply connected surface of constant Gauss curvature −1, studied through models like the Poincaré disk because it cannot sit in ordinary 3-space.
Hyperbolic plasmons
Hyperbolic plasmons are surface plasmon polaritons whose isofrequency contour is a hyperbola rather than an ellipse, giving highly directional propagation and an extremely large density of states.
Hyperbolic polariton
A hyperbolic polariton is a hybrid light–matter quasiparticle that propagates in anisotropic media with permittivity components of opposite sign, giving hyperbolic dispersion, high confinement, and directional energy flow.
Hyperbolic polariton ray optics
Hyperbolic polariton ray optics treats light-matter waves called hyperbolic polaritons as rays, like geometrical optics, in anisotropic crystals such as hexagonal boron nitride and molybdenum trioxide.