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Levenberg–Marquardt algorithm
The Levenberg–Marquardt algorithm, also known as the Levenberg–Marquardt method or damped least squares, is an iterative numerical method for nonlinear least squares that interpolates between Gauss–Newton and gradient descent.
Levene's test
Levene's test is a statistical test of whether several independent samples come from populations with equal variances, proposed by Howard Levene in 1960 and used to check an assumption of ANOVA.
Levent Alpöge
Levent Alpöge is an American–Turkish number theorist known for results on elliptic curves and a negative solution of Hilbert's tenth problem over rings of integers.
Lever escapement
The lever escapement is a detached escapement for clocks and watches, attributed to English watchmaker Thomas Mudge around 1754 and still standard in most mechanical watches.
Leverage (statistics)
Leverage, in statistics, measures how far an observation's independent-variable values lie from the center of the others in a regression, indicating its potential to move the fitted line.
Levi graph
The Levi graph, also called the incidence graph, is the bipartite graph of an incidence structure, with vertices for points and lines and edges for incidences.
Levi-Civita connection
The Levi-Civita connection, also known as the Riemannian or Christoffel connection, is the unique torsion-free, metric-compatible way to differentiate tensor fields on a Riemannian manifold.
Levi-Civita field
The Levi-Civita field is a non-Archimedean ordered field extension of the real numbers containing infinitesimals, the smallest such extension that is real closed and Cauchy complete.
Levi-Civita symbol
The Levi-Civita symbol, also called the permutation symbol, is a collection of numbers based on the sign of a permutation, equal to +1, −1, or 0.
Leviathan and the Air-Pump
Leviathan and the Air-Pump is a 1985 book by Steven Shapin and Simon Schaffer examining the Hobbes-Boyle dispute over experiment, arguing that solutions to knowledge are solutions to social order.
Levitated dipole
A levitated dipole is a magnetic confinement concept for fusion plasma in which a freely floating superconducting ring generates the field, proposed by Akira Hasegawa in 1987.
Levitated optomechanics
Levitated optomechanics is the study of light interacting with small particles suspended in vacuum, offering extreme environmental isolation for quantum tests and ultrasensitive force sensing.
Levobupivacaine
Levobupivacaine, sold under the brand name Chirocaine, is a long-acting local anesthetic developed as a safer alternative to bupivacaine, with lower cardiac and central nervous system toxicity.
Levoglucosenone
Levoglucosenone (LGO) is a chiral bicyclic ketone with the formula C6H6O3, produced from cellulose by acid-catalyzed pyrolysis and used for polymers, green solvents, and fine chemicals.
Levomethamphetamine
Levomethamphetamine, also called levmetamfetamine or l-desoxyephedrine, is the levorotatory isomer of methamphetamine, a weaker CNS stimulant sold over the counter in American nasal decongestant vapor inhalers.
Levulinic acid
Levulinic acid, also known as acetopropionic acid, is a five-carbon keto carboxylic acid made from biomass and used as a platform chemical for fuels and solvents.
Levulinic acid to gamma-valerolactone
The conversion of levulinic acid to gamma-valerolactone (GVL) is the catalytic hydrogenation of biomass-derived levulinic acid to GVL, a key step in making renewable fuels and solvents.
Lévy distribution
The Lévy distribution is a heavy-tailed continuous probability distribution with no finite mean or variance, arising as the first time Brownian motion reaches a fixed level.
Lévy flight
A Lévy flight is a random walk whose step lengths follow a heavy-tailed power-law distribution, named for Paul Lévy; the rare long jumps make the motion superdiffusive.
Lévy measure
A Lévy measure assigns to each set of jump sizes the expected number of jumps per unit time in a Lévy process, allowing infinitely many small jumps.
Lévy process
A Lévy process is a stochastic process with stationary, independent increments and càdlàg paths, combining continuous motion with abrupt jumps and generalizing Brownian motion and the Poisson process.
Lévy–Khintchine formula and Lévy–Itô decomposition
The Lévy–Khintchine formula and Lévy–Itô decomposition characterize Lévy processes: the formula encodes the distribution in a drift, Gaussian, and jump triplet, while the decomposition builds the process from those parts.
Lewis acid catalysis
Lewis acid catalysis is the acceleration of organic reactions by an electron-pair-accepting species, such as AlCl3 or BF3, that binds a basic site of a substrate.
Lewis acid–photoredox cooperative catalysis
Lewis acid–photoredox cooperative catalysis is a dual-catalysis strategy in organic synthesis in which a photoredox catalyst generates radical intermediates under visible light while a Lewis acid, often chiral, controls stereochemistry.
Lewis acids and bases
Lewis acids and bases, defined by Gilbert N. Lewis in 1923, are chemical species classified by electron pairs: a Lewis acid accepts a pair, a Lewis base donates one.
Lewis Boss
Lewis Boss (1846–1912) was an American astronomer who directed the Dudley Observatory in Albany, New York, from 1876, and compiled the Preliminary General Catalogue of 6188 stars in 1910.
Lewis Fry Richardson
Lewis Fry Richardson (1881–1953) was an English mathematician, physicist, meteorologist, and pacifist who pioneered numerical weather forecasting and later compiled quantitative statistics on the causes of war.
Lewis G. Longsworth
Lewis G. Longsworth was an American chemist and biochemist who spent his entire career, 1928 to 1970, at the Rockefeller Institute in New York, known for electrophoresis and diffusion measurements.
Lewis H. Nosanow
Lewis H. Nosanow is a physicist who co-suggested in 1976 that spin-polarized hydrogen stays a gas at any temperature, launching the search for Bose–Einstein condensation.
Lewis Hastings Sarett
Lewis Hastings Sarett was an American organic chemist at Merck & Co. who achieved the first synthesis of cortisone in 1944, during World War II.