All articles starting with H
20,046 articles
Higher-dimensional class field theory
Higher-dimensional class field theory extends abelian class field theory to higher local fields and arithmetic schemes, due to Parshin and Kato, replacing the multiplicative group with Milnor K-groups.
Higher-dimensional supergravity
Higher-dimensional supergravity is supergravity formulated in spacetime dimensions above the four of ordinary general relativity; the eleven-dimensional theory of Cremmer, Julia, and Scherk (1978) is maximal and underlies M-theory.
Higher-energy collisional dissociation
Higher-energy collisional dissociation (HCD) is a fragmentation method in tandem mass spectrometry in which ions collide with gas in a dedicated cell; lacking CID's low-mass cutoff, it suits TMT quantification.
Higher-order aberration theory
Higher-order aberration theory describes optical wavefront errors by extending the aberration expansion beyond the five Seidel terms, adding fifth-, seventh-, and higher-order terms represented chiefly by Zernike polynomials.
Higher-order abstract syntax
Higher-order abstract syntax (HOAS) represents object-language variable binding using meta-language functions, coined by Pfenning and Elliott (PLDI 1988). It automates alpha-conversion and substitution, works natively in LF, Twelf, λProlog, Abella and Beluga, and spawns weak and parametric HOAS variants for Coq.
Higher-order function
A higher-order function is a function that takes one or more functions as arguments, returns a function as its result, or both, as in map, filter, and fold.
Higher-order logic
Higher-order logic (HOL), also called simple type theory or Church's type theory, extends first-order logic by quantifying over predicates and functions via the simply typed lambda calculus; standard semantics is not axiomatizable, Henkin semantics is complete, and HOL underlies proof assistants like Isabelle/HOL and HOL Light.
Higher-order post-Newtonian effects
Higher-order post-Newtonian effects are corrections to Newtonian gravity and first-post-Newtonian relativity, covering 2PN through 4PN two-body dynamics, gravitational-wave tail terms, and the frontier at 5PN and 6PN.
Higher-order singular value decomposition
The higher-order singular value decomposition (HOSVD), also known as higher-order SVD, is a multilinear generalization of the matrix SVD, introduced by De Lathauwer, De Moor, and Vandewalle in 2000.
Higher-order thinking
Higher-order thinking (HOT), or HOTS, is cognitive activity beyond recall and comprehension, covering analysis, evaluation, creation, critical thinking, and problem-solving. Rooted in Bloom's 1956 taxonomy's upper levels, it is widely taught and assessed, with meta-analyses of project-based learning reporting medium effects (d ≈ 0.58–0.75).
Higher-order topological insulator
A higher-order topological insulator (HOTI) is an insulating material whose surfaces are gapped but which hosts protected states at corners or hinges, predicted in 2017.
Higher-order topological insulator in bismuth
Bismuth is a higher-order topological insulator, a crystalline solid with insulating bulk and surfaces but conducting, topologically protected hinge modes, established in a 2018 Nature Physics study.
Higher-order topological mechanical metamaterials
Higher-order topological mechanical metamaterials are architected structures whose elastic waves or deformations localize at corners rather than edges, reproducing higher-order topological insulator physics in mechanical platforms.
Highest 2 Lowest
Highest 2 Lowest is Spike Lee's 2025 crime thriller, a New York reinterpretation of Kurosawa's High and Low, starring Denzel Washington as music mogul David King in a $17.5 million ransom plot; his fifth film with Washington, released by A24 and Apple TV+.
Highest averages method
Highest averages (divisor) methods allocate legislative seats proportionally by dividing party votes by sequences such as D'Hondt's 1, 2, 3 or Sainte-Laguë's odd numbers; D'Hondt favors large parties, Sainte-Laguë is unbiased.
Highest in the Room
Highest in the Room, also styled HIGHEST IN THE ROOM, is a 2019 Travis Scott single produced by OZ and NIK D with Mike Dean; it debuted at No. 1 on the Billboard Hot 100 and peaked at No. 2 in the UK.
Highest median voting rules
Highest median voting rules, chiefly majority judgment (jugement majoritaire) by Balinski and Laraki, elect the candidate with the highest median grade on a common evaluation scale, unlike approval or ranked methods.
Highest temperature recorded on Earth
The highest temperature recorded on Earth is 56.7 °C (134 °F), measured at Furnace Creek Ranch in Death Valley, California, on 10 July 1913, though a 2025 reanalysis contests it.
Highest unclimbed mountain
Highest unclimbed mountain: Gangkhar Puensum (གངས་དཀར་སྤུན་གསུམ), 7,570 m, Bhutan's highest peak, unclimbed due to Bhutan's 1994/2003 mountaineering bans; five failed attempts 1985–1986.
Highest-weight theory
Highest-weight theory is the branch of representation theory classifying representations of semisimple Lie algebras and Lie groups by a single linear functional, the highest weight, attached to each irreducible representation.
Highgate
Highgate is a hilltop north London district on the Camden–Haringey boundary, a former tollgate village on the Bishop of London's estate, known for Highgate School (1565), Highgate Cemetery, Waterlow Park, conservation areas, and Northern Line access.
Highgate Cemetery
Highgate Cemetery (St James's Cemetery of Highgate), north London burial ground opened 1839 by the London Cemetery Company, third of the Magnificent Seven; West and East cemeteries, Karl Marx's grave, Grade I registered, over 170,000 buried.
Highgate School
Highgate School (Sir Roger Cholmeley's School at Highgate), a co-educational independent day school in North London founded by royal charter in 1565, educates pupils aged 3-19; selective entry, means-tested bursaries up to 100% of fees, ISI-rated 'excellent', co-educational since 2004.
Highgrove House
Highgrove House is a Grade II listed country house near Tetbury, Gloucestershire, bought by the Duchy of Cornwall in 1980 as the country home of King Charles III, whose organic gardens are open to the public.
Highguard
Highguard: free-to-play 3v3 PvP raid shooter by Wildlight Entertainment (ex-Apex Legends/Titanfall devs), revealed at The Game Awards 2025, launched January 26, 2026, shut down March 12, 2026 after overwhelmingly negative reception.
Highland
A highland is a broad elevated region of hills, mountains, or plateau standing above surrounding lowland; no universal altitude defines it, only elevation, relief, and contrast with neighboring lowlands.
Highland (council area)
Highland is one of Scotland's 32 council areas, governed by The Highland Council with 74 councillors across 21 multi-member wards. Population 237,260 (2025), 7th of 32; covers a third of Scotland's land area.
Highland Capital Partners
Highland Capital Partners is a venture capital firm in Cambridge, Massachusetts, founded in 1987, investing in consumer and enterprise technology companies across the United States, China, and the United Kingdom.
Highland cattle
Highland cattle: hardy Scottish beef breed from the Highlands and western islands, long shaggy coat, sweeping horns, Herd Book 1885, cows 900-1,300 lb, docile, used for conservation grazing.
Highland Clearances
The Highland Clearances: evictions of Highland and Island tenants, c.1760–1860, for sheep farming; Sutherland clearances, Patrick Sellar, Great Highland Famine, Crofters War, and the 1886 Crofters Act.