42,772 articles
Harald Fritzsch
Harald Fritzsch (1943–2022) was a German theoretical physicist who, with Murray Gell-Mann and Heinrich Leutwyler, co-founded quantum chromodynamics, the theory of the strong interaction, and later shaped quark mass matrices and neutrino physics.
Harald Gießen
Harald Gießen, also spelled Harald Giessen, is a German physicist and professor at the University of Stuttgart since 2005, known for founding 3D-printed microoptics and imaging plasmonic skyrmions.
Harald Lesch
Harald Lesch (born 1960 in Gießen) is a German theoretical astrophysicist and professor at LMU Munich, known for the ZDF shows Leschs Kosmos and Terra X.
Harald R. Telle
Harald R. Telle is a German physicist at the Physikalisch-Technische Bundesanstalt in Braunschweig who helped build optical interval dividers and proposed self-referencing for frequency combs in 1999.
Harald Rose
Harald Rose (1935–2026) was a German theoretical physicist and electron optician whose hexapole corrector, proposed in 1990, enabled atomic-resolution electron microscopy and won him the 2020 Kavli Prize in Nanoscience.
Harald Sverdrup (oceanographer)
Harald Sverdrup was a Norwegian oceanographer who directed the Scripps Institution of Oceanography from 1936 to 1948; the ocean-transport unit sverdrup is named for him.
Haraldur Sigurðsson
Haraldur Sigurðsson, born 1939 in Stykkishólmur, Iceland, is an Icelandic volcanologist and geochemist, emeritus professor at the University of Rhode Island known for work on the AD 79 Vesuvius eruption and Icelandic rhyolites.
Hard and soft science
Hard and soft science is an informal English classification ranking academic fields, treating physics and the natural sciences as hard and sociology and psychology as soft.
Hard sphere model
The hard sphere model is a statistical mechanics model of impenetrable spheres that repel infinitely on contact and otherwise exert no force, serving as a key reference system.
Hard X-ray photoelectron spectroscopy
Hard X-ray photoelectron spectroscopy (HAXPES) is X-ray photoelectron spectroscopy performed with photon energies above 2 keV, reaching buried layers and interfaces several tens of nanometers deep.
Hard-core point process
A hard-core point process is a spatial stochastic model where no two points lie closer than a fixed minimum distance, modeling repulsive patterns like cells and trees.
Hardening (metallurgy)
Hardening in metallurgy is the increase of a metal's resistance to plastic deformation, achieved by obstructing dislocation motion through mechanisms such as work hardening, precipitation hardening, and quenching to martensite.
Hardening law
A hardening law is a rule in plasticity theory specifying how a material's yield surface changes as it plastically deforms, chiefly by isotropic expansion or kinematic translation.
Hardness
Hardness is the resistance of a material to localized deformation, measured by indentation tests such as Rockwell, Brinell, and Vickers, or by scratch tests like the Mohs scale.
Hardware-efficient ansatz
A hardware-efficient ansatz (HEA) is a parameterized quantum circuit using only gates and qubit connections native to the target device, proposed by Kandala et al. in 2017 for VQE.
Hardy inequality
The Hardy inequality is a result in analysis bounding averaged sequences or functions by a constant times the original, introduced by G. H. Hardy in 1920.
Hardy space
The Hardy space H^p, also called a Hardy class, is a space of analytic functions with bounded integral means, introduced by G. H. Hardy in 1915.
Hardy–Littlewood circle method
The Hardy–Littlewood circle method is an analytic number theory technique for counting integer representations as sums of powers or primes, arising from Hardy and Ramanujan's 1917 partition work.
Hardy–Littlewood conjecture
The Hardy–Littlewood conjecture, made by G. H. Hardy and John E. Littlewood in 1923, predicts how often patterns of primes occur and generalizes the twin prime conjecture.
Hardy–Littlewood maximal function
The Hardy–Littlewood maximal function is an operator in harmonic analysis that replaces a function with its supremal averages over balls, introduced by Hardy and Littlewood in 1930.
Hari Shroff
Hari Shroff is an American optical microscopist known for building fast, gentle super-resolution and light-sheet microscopes for living specimens, and winner of a 2010 PECASE award.
Harish-Chandra
Harish-Chandra (1923–1983) was an Indian-born mathematician at the Institute for Advanced Study who transformed the representation theory of semisimple Lie groups into a major field central to modern mathematics.
Harish-Chandra isomorphism
The Harish-Chandra isomorphism is an algebra isomorphism identifying the center of the universal enveloping algebra of a semisimple Lie algebra with Weyl-group-invariant polynomials on a Cartan subalgebra.
HARKing
HARKing, hypothesizing after the results are known, is presenting a post hoc hypothesis in a research report as if it were made in advance, named by N. L. Kerr in 1998.
Harland Goff Wood
Harland Goff Wood (1907–1991) was an American biochemist at Case Western Reserve University who proved in 1935 that heterotrophic organisms fix carbon dioxide, work honored by the 1989 National Medal of Science.
Harlow Shapley
Harlow Shapley was an American astronomer who located the center of the Milky Way in Sagittarius and directed the Harvard College Observatory from 1921 to 1952.
Harlow's monkey experiments
Harlow's monkey experiments were Harry Harlow's studies at the University of Wisconsin–Madison, begun in 1957, showing infant monkeys preferred cloth surrogates over milk-providing wire ones.
Harm‐Anton Klok
Harm-Anton Klok, born 1971 in the Netherlands, is a polymer chemist and full professor at EPFL, where he leads the Polymers Laboratory and studies polymer brushes, biologically inspired polymers, and precision polymerization.
Harmattan
The Harmattan, also called the doctor, is a dry, dust-bearing northeasterly wind over West Africa from late November to mid-March, carrying Saharan dust toward the Gulf of Guinea.
Harmine
Harmine is a β-carboline alkaloid first isolated in 1847 from Syrian rue, the principal active alkaloid of ayahuasca, now under study for regenerating insulin-producing beta cells in diabetes.