All articles starting with U
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Unitary Fermi gas
A unitary Fermi gas is a dilute gas of fermionic atoms with a diverging s-wave scattering length, tuned by a magnetic field, making it the most strongly interacting nonrelativistic system known.
Unitary group
The unitary group U(n) is the group of n × n complex matrices that preserve the Hermitian inner product, with dimension n² as a compact Lie group.
Unitary matrix
A unitary matrix is a complex square matrix whose conjugate transpose equals its inverse, the complex analog of a real orthogonal matrix that preserves lengths.
Unitary operator
A unitary operator is a linear operator whose adjoint equals its inverse, preserving inner products; it is central to quantum mechanics, describing symmetries and time evolution.
Unitary representation
A unitary representation is a continuous homomorphism from a topological group into the unitary operators on a Hilbert space, central to harmonic analysis and quantum mechanics.
Unitary state
Unitary state: a state where the central government is supreme and subnational governments hold only delegated, revocable powers. 168 of 193 UN member states; distinct from federal and quasi-federal systems.
Unité d'Habitation
The Unité d'Habitation, known locally as the Cité Radieuse, is a seventeen-storey reinforced-concrete apartment block in Marseille, France, designed by Le Corbusier as a prototype for postwar mass housing.
UNITE HERE
UNITE HERE: North American labor union of about 300,000 hotel, gaming, food service, laundry, textile, and airport workers, formed by the 2004 merger of UNITE and HERE, AFL-CIO affiliated, led by president Gwen Mills since 2024.
Unite Private Networks
Unite Private Networks was an American commercial fiber-optic network provider founded in 1998 in Kansas City, Missouri, serving schools, governments, hospitals, and enterprises rather than homes.
Unite the Right rally
The Unite the Right rally was a white nationalist rally in Charlottesville, Virginia, in August 2017, held to protest the removal of a Robert E. Lee statue.
Unite USA Inc.
Unite USA Inc., doing business as Unite Us, is a New York-based technology company founded in 2013 whose platform connects health and human services; it has raised over $184 million.
UNITE with Tomorrowland Italy
UNITE with Tomorrowland Italy was the Italian edition of the UNITE satellite series linked to Tomorrowland in Belgium, held on 28 July 2018 at Parco di Monza near Milan.
United 2026 FIFA World Cup bid
United 2026 FIFA World Cup bid: joint Canada-Mexico-United States hosting proposal announced April 2017, scored 4.0/5 by FIFA, and won the June 2018 Congress vote with 134 of 200 votes (67%) over Morocco, securing the first 48-team, three-country World Cup.
United 93 (film)
United 93 is a 2006 American-British-French docudrama directed by Paul Greengrass, telling in real time the story of the hijacked United Flight 93 on September 11, 2001.
United Abominations
United Abominations (2007) is Megadeth's eleventh studio album and first for Roadrunner Records, with Mustaine, the Drover brothers, and James LoMenzo; includes the Cristina Scabbia duet re-recording of À Tout le Monde.
United Africans Transformation
United Africans Transformation (UAT), South African Pan-African party registered 15 November 2022; won 35,678 votes (0.22%) and one National Assembly seat in 2024, strongest in Limpopo; led by Dr. Wonder Mahlatsi.
United Aircraft Corporation (Объединённая авиастроительная корпорация)
United Aircraft Corporation (Объединённая авиастроительная корпорация, OAK) is a Russian state aerospace holding company created by decree in 2006, consolidating the Sukhoi, MiG, Ilyushin, and Tupolev design bureaus.
United Airlines
United Airlines is a major American airline headquartered in Chicago and owned by United Airlines Holdings, tracing to 1926 air mail routes and merged with Continental Airlines in 2010.
United Airlines Flight 173
United Airlines Flight 173 was a scheduled DC-8 flight from New York that crashed near Portland, Oregon, in 1978 after all four engines flamed out from fuel exhaustion.
United Airlines Flight 175
United Airlines Flight 175 was a Boeing 767 Boston Logan-to-Los Angeles flight hijacked by five al-Qaeda terrorists on September 11, 2001 and flown into the World Trade Center South Tower at 9:03:11 a.m., killing all aboard.
United Airlines Flight 232
United Airlines Flight 232 was a DC-10 flight from Denver to Chicago that crashed at Sioux City, Iowa, on July 19, 1989, killing 111 of 296 aboard; 185 survived.
United Airlines Flight 585
United Airlines Flight 585 was a Boeing 737-200 flight that crashed on approach to Colorado Springs, Colorado, on March 3, 1991, killing all 25 people aboard.
United Airlines Flight 811
United Airlines Flight 811 was a scheduled Boeing 747 flight that suffered explosive decompression near Honolulu in 1989 when its cargo door opened in flight.
United Airlines Flight 93
United Airlines Flight 93 was a Boeing 757 flying from Newark to San Francisco, hijacked on September 11, 2001, that crashed in Pennsylvania after passengers fought back.
United and uniting churches
United and uniting churches, also called united or federation churches, are Christian denominations formed by merging churches of different traditions; the World Council of Churches counts about 50 worldwide.
United Arab Emirates (الإمارات العربية المتحدة)
United Arab Emirates (الإمارات العربية المتحدة), federation of seven emirates founded 2 December 1971 after British withdrawal from the Trucial States; capital Abu Dhabi; constitutional federation with Federal Supreme Council, 40-seat Federal National Council, oil- and trade-based economy.
United Arab Emirates Air Force
United Arab Emirates Air Force and Air Defence (UAEAF), founded 13 May 1968 as Abu Dhabi's Air Wing; flies about 135 fighters (76 F-16E/F Block 60, 59 Mirage 2000-9) with 80 Rafale F4 on order since 2021; fought in Yemen and against Daesh.
United Arab Emirates Armed Forces
The United Arab Emirates Armed Forces are the unified military of the UAE, unified under one command on 6 May 1976 and overseen by the Ministry of Defence.
United Arab Emirates Army
The United Arab Emirates Army is the land branch of the UAE Armed Forces, unified on 6 May 1976 from emirate forces and the Trucial Oman Scouts; it fields mixed French and other equipment and has served in Kuwait, Somalia, Afghanistan, Libya, and Yemen.
United Arab Emirates dirham (درهم إماراتي)
The United Arab Emirates dirham (درهم إماراتي), the UAE's currency issued by its central bank, was introduced in 1973 and pegged to the US dollar at 3.6725 since 1997.