All articles A–Z
519,064 articles
Elliptic Curve Digital Signature Algorithm
The Elliptic Curve Digital Signature Algorithm (ECDSA) is a public-key signature algorithm over elliptic curves, specified by NIST in FIPS 186-5 and used in TLS and Bitcoin.
Elliptic flow
Elliptic flow is the second harmonic coefficient (v2) of particle emission in noncentral heavy-ion collisions, the principal signature of fluid-like behavior in the quark-gluon plasma.
Elliptic function
An elliptic function is a meromorphic function of a complex variable that is doubly periodic, with two periods whose ratio is not real; it arose from inverting elliptic integrals.
Elliptic integral
Elliptic integral is a special function, first studied by John Wallis in 1655 regarding the arc length of an ellipse. It is an integral involving cubic or quartic polynomials.
Elliptic orbit
An elliptic orbit, also called an elliptical orbit, is a closed, gravitationally bound path in which one body follows an ellipse around another, as the planets do around the Sun.
Elliptic partial differential equation
An elliptic partial differential equation, or elliptic PDE, is a PDE whose highest-order terms have no real characteristic directions, exemplified by the Laplace and Poisson equations governing steady-state physics.
Elliptic-curve cryptography
Elliptic-curve cryptography (ECC) is a form of public-key cryptography, proposed by Neal Koblitz and Victor Miller in 1985, whose security rests on the elliptic curve discrete logarithm problem and achieves RSA-comparable security with far smaller keys.
Elliptic-curve Diffie–Hellman
Elliptic-curve Diffie–Hellman (ECDH) is a key agreement protocol in which two parties derive a shared secret key over an insecure channel by exchanging points on an elliptic curve.
Elliptical copula
An elliptical copula is the copula of an elliptically contoured distribution, capturing its dependence structure separately from its marginals; examples include the Gaussian and Student t copulas.
Elliptical distribution
An elliptical distribution is a multivariate probability distribution whose density is constant on ellipsoids centered at a location vector, generalizing the multivariate normal distribution and widely applied in statistics, econometrics, and financial risk modeling.
Elliptical galaxy
An elliptical galaxy is a smooth, oval-shaped galaxy of old, red stars orbiting in random directions, with little gas or dust and little ongoing star formation.
Elliptical polarization
Elliptical polarization is the most general polarization state of a transverse wave, in which the electric field vector traces an ellipse; linear and circular polarization are special cases.
Elliptical trainer
Elliptical trainer, also called cross-trainer: stationary exercise machine with oval pedal path and moving handlebars for low-impact full-body cardio. Invented commercially by Precor's EFX 544 in 1995; crank-linkage drive, adjustable resistance and stride.
Ellis (TV series)
Ellis, also Inspector Ellis, is a 2024 British crime drama starring Sharon D Clarke as DCI Ellis, who takes over failing murder investigations across northern England with DS Harper (Andrew Gower); three series-1 films plus a 2026 four-episode series 2 on Channel 5 and Acorn TV.
Ellis B. Cowling
Ellis B. Cowling (1932–2021) was an American forest biologist at North Carolina State University, a National Academy of Sciences member known for acid rain research.
Ellis Beach Surf Life Saving Club
Ellis Beach SLSC, a volunteer surf lifesaving club founded 1957 at Ellis Beach, 20 km north of Cairns, Queensland; patrols April to November, 300 members, new beachfront clubhouse opened 2026 with $5.2 million government funding.
Ellis Bridge
Ellis Bridge, officially renamed Swami Vivekanand Bridge, is a heritage steel truss bridge across the Sabarmati River in Ahmedabad, Gujarat, built in 1892 as a symbol of the city.
Ellis Burks
Ellis Burks (born 1964) is a former MLB outfielder and designated hitter for the Red Sox, White Sox, Rockies, Giants, and Indians; 2,107 hits, 352 home runs, 1996 NL MVP third place, 2004 World Series champion.
Ellis County, Texas, United States
Ellis County, Texas, county established December 20, 1849 from Navarro County, named for Richard Ellis; seat Waxahachie, 30 miles south of Dallas; 935.8 sq mi; population 192,455 (2020) growing to about 240,867 (2025).
Ellis Englesberg
Ellis Englesberg (1921–2013) was an American bacterial geneticist best known for discovering positive control of gene expression, showing that regulatory proteins can switch genes on, through his genetic analysis of the E. coli arabinose operon.
Ellis Genge
Ellis Genge (born 1995) is an English rugby union loosehead prop for Bristol Bears with 71 England caps, a 2025 British & Irish Lions tourist, former Leicester Tigers captain, and England co-captain.
Ellis Howard
Ellis Howard (Ellis Francis Howard) is a Liverpool-born English actor and writer, BAFTA-nominated for playing Byron in the BBC's What It Feels Like for a Girl (2025); also known for Red Rose, Help, and Catherine the Great.
Ellis Island
Ellis Island, in New York Harbor, was the main U.S. immigrant inspection station 1892–1954, processing almost 12 million arrivals; now part of Statue of Liberty National Monument, it houses the National Museum of Immigration and is reachable only by Statue City Cruises ferry.
Ellis Kolchin
Ellis Kolchin (1916–1991) was an American mathematician at Columbia University, pupil and successor of Joseph Fels Ritt, who shaped differential algebra and created differential algebraic groups.
Ellis L. Johnson
Ellis L. Johnson (1938–2024) was an operations research mathematician known for foundational work in integer programming, who spent 25 years at IBM and later held a chaired professorship at Georgia Tech.
Ellis L. Reinherz
Ellis L. Reinherz is an immunologist, Chief of the Laboratory of Immunobiology at Dana-Farber Cancer Institute and Harvard professor, known for defining human T-cell functional subsets and T-cell receptor structure.
Ellis Short
Ellis Short is an Irish-American private equity financier and co-founder of Dallas-based Lone Star Funds who owned Sunderland from 2008 to 2018, investing over £200m.
Ellis Simms
Ellis Reco Simms (born 2001) is an English striker for Coventry City, formerly Everton, with loans at Blackpool, Hearts, and Sunderland; he won the 2025-26 Championship with Coventry.
Ellis-Van Creveld syndrome
Ellis-Van Creveld syndrome, also called chondroectodermal dysplasia, is an inherited skeletal disorder causing short limbs, extra fingers, nail and tooth abnormalities, and congenital heart defects.
Ellison Goodall
Ellison Goodall (Ellison Goodall Bishop), born 1954, American distance runner; 1979 World Cross Country bronze medallist, women's half marathon world record 75:01 (Winston-Salem, 1979), 1978 AAU 10,000m champion, Duke Hall of Famer.