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Lanthanum superhydride
Lanthanum superhydride is a hydrogen-rich compound of lanthanum that superconducts at about 250 kelvin under 170 gigapascals of pressure, reported in 2019 as the highest confirmed critical temperature.
Lanthanum-doped barium stannate
Lanthanum-doped barium stannate (La:BaSnO3, abbreviated LBSO) is a transparent conducting oxide studied as an indium-free alternative to ITO, with the highest room-temperature electron mobility among wide-band-gap semiconductors.
Lanthionine
Lanthionine is a nonproteinogenic sulfur-containing amino acid in which two alanine residues are linked by a thioether bridge, first isolated from alkali-treated wool in 1941.
Lap shear test
The lap shear test, also known as the single-lap joint test, measures adhesive bond strength by pulling two overlapping strips in tension until the joint fails, reported in MPa or psi.
LAPACK
LAPACK (Linear Algebra Package) is a freely available Fortran library, first released in 1992, for solving linear systems, least-squares, eigenvalue, and singular value problems for dense and banded matrices.
Lapatinib
Lapatinib, sold as Tykerb and Tyverb, is an oral drug for HER2-positive breast cancer that blocks the HER2 and EGFR kinases. It was approved in the US in 2007.
Lapilli
Lapilli, meaning "little stones" in Italian, are fragments of lava or rock between 2 and 64 mm across blasted into the air by volcanic explosions, a middle size class of tephra.
Lapis lazuli
Lapis lazuli is a deep-blue metamorphic rock composed mainly of lazurite, calcite, and pyrite, prized as a gem and as the source of ultramarine pigment.
Laplace approximation (Bayesian inference)
The Laplace approximation, also called the posterior normal approximation, approximates a Bayesian posterior or intractable integral like the marginal likelihood with a Gaussian fitted at the mode.
Laplace distribution
The Laplace distribution, also called the double exponential distribution, is a continuous probability distribution with a sharp peak and exponential tails, introduced by Pierre-Simon Laplace in 1774.
Laplace operator
The Laplace operator, or Laplacian, is a differential operator summing a function's second partial derivatives, central to physics equations like Laplace's, the wave, and the Schrödinger equation.
Laplace plane
The Laplace plane is the reference plane about which a satellite's orbit precesses on average, an idea Pierre-Simon Laplace recognized in 1805 in his study of Jupiter's satellites.
Laplace resonance
The Laplace resonance is a three-body orbital resonance in which Jupiter's moons Io, Europa, and Ganymede orbit in a 1:2:4 period ratio, driving tidal heating.
Laplace transform
The Laplace transform, also called the Laplace transformation, is an integral transform that converts a function of time into a function of a complex variable.
Laplace–Beltrami operator
The Laplace–Beltrami operator, introduced by Eugenio Beltrami in the 1860s, generalizes the Laplace operator to Riemannian manifolds as the divergence of the gradient, depending only on the metric.
Laplace–Runge–Lenz vector
The Laplace–Runge–Lenz vector, also called the LRL or Runge–Lenz vector, is a conserved quantity of the Kepler problem whose conservation forces bound orbits to be closed, non-precessing ellipses.
Laplace–Stieltjes transform
The Laplace–Stieltjes transform of a nonnegative random variable X is E(e^{-sX}), defined for s ≥ 0 as the Stieltjes integral of e^{-sx} against the distribution function, applying to distributions with atoms or densities alike.
Laplace's demon
Laplace's demon, also called the Laplacian demon, is a hypothetical intelligence imagined by Pierre-Simon Laplace in 1814 that could predict the entire future from knowing the universe's complete present state.
Laplace's equation
Laplace's equation, also known as Laplace's differential equation, is the second-order partial differential equation Δu = 0, the prototype of elliptic equations; its solutions are harmonic functions describing gravitational and electrostatic potentials.
Laplace's method
Laplace's method is a technique of asymptotic analysis for estimating Laplace integrals with a large parameter, using only the region near the exponent's maximum; it dates to Laplace's 1774 memoir.
Laplacian matrix
The Laplacian matrix, also called the graph Laplacian or Kirchhoff matrix, is a graph matrix L = D − A whose eigenvalues reveal connectivity, spanning trees, and clustering.
Lapo Bogani
Lapo Bogani is an Italian experimental physicist and chemist working on molecular magnetism, molecular spintronics, and graphene nanoribbon quantum devices, chair at the University of Florence since 2023.
Lapse and shift
The lapse function and shift vector are gauge quantities in the 3+1 decomposition of general relativity that control how spacetime is sliced and how coordinates move between slices.
Lapse rate
The lapse rate, also called the atmospheric lapse rate, is the rate at which temperature falls with height in the atmosphere; its size measures atmospheric stability.
lapse rate feedback
The lapse rate feedback is a climate feedback in which warming changes the vertical temperature profile, altering radiation to space; it is negative in the tropics.
Lapyrium
Lapyrium (lapirium chloride, E-607, CAS 6272-74-8) is a quaternary ammonium cationic surfactant with biocidal activity, FDA-recognized since 1982 and used in cosmetics as a surfactant and antimicrobial, currently at about 0.03% concentration.
Laramide orogeny
The Laramide orogeny was a mountain-building episode from about 75 to 40 million years ago that built much of the Rocky Mountains through thick-skinned, basement-cored uplifts.
Large Area Telescope
The Large Area Telescope (LAT) is the primary instrument on NASA's Fermi Gamma-ray Space Telescope, a pair-conversion imaging gamma-ray telescope surveying the sky from about 20 MeV to more than 300 GeV since 2008.
Large Binocular Telescope
The Large Binocular Telescope (LBT) is an optical and infrared observatory on Mount Graham, Arizona, whose two 8.4 m mirrors give it the collecting area of an 11.8 m telescope.
Large cardinal
A large cardinal, also called a large cardinal axiom, is an uncountable cardinal so large that its existence is unprovable in ZFC, set theory's standard axioms.