42,772 articles
Del
Del, written ∇ and also called nabla, is the vector differential operator of vector calculus; combined with three kinds of multiplication it yields the gradient, divergence, and curl.
Delafossite
Delafossite is a copper iron oxide mineral, CuFeO₂, first described in 1873 from Russia and named for Gabriel Delafosse; it typifies the layered delafossite oxide family.
Delamination
Delamination is the failure of the bond between a material's layers, causing them to separate along a plane parallel to its surface in concrete, composites, and thin films.
Delamination tectonics
Delamination tectonics is the geodynamic process in which dense mantle lithosphere peels away from the overlying crust and sinks into the asthenosphere, introduced by Peter Bird in 1979.
Delaunay triangulation
The Delaunay triangulation, also known as the Delone triangulation or Delaunay tessellation, is a triangulation of a point set whose triangle circumcircles contain no other points.
Delay differential equation
A delay differential equation is a differential equation whose rate of change depends on past states, not only the present one, so the system carries a memory.
Delayed detached eddy simulation
Delayed detached eddy simulation (DDES) is a hybrid RANS–LES turbulence modeling approach, introduced by Spalart and colleagues in 2006, that runs RANS in attached boundary layers and switches to LES in separated flow.
Delayed neutron
A delayed neutron is a neutron emitted by a fission product seconds to minutes after fission, following beta decay of a neutron-rich precursor, with fewer than 1% of fission neutrons delayed.
Delayed-choice quantum eraser
The delayed-choice quantum eraser is a quantum optics experiment first realized by Kim, Yu, Kulik, and Shih in 2000, in which which-path information is erased after the photon is detected.
Delft-FEWS
Delft-FEWS, short for Flood Early Warning System, is a platform by the Dutch institute Deltares that integrates data and models for operational flood forecasting, introduced in 2002.
Delft3D
Delft3D is a software suite simulating hydrodynamics, sediment transport, waves, and water quality in coastal, estuarine, and river waters, developed by WL | Delft Hydraulics.
Delia W. Oppo
Delia W. Oppo is a paleoceanographer and emeritus research scholar at Woods Hole Oceanographic Institution in Massachusetts, an AGU Fellow known for reconstructing 2,000 years of Indo-Pacific warm pool temperatures.
Deliang Chen
Deliang Chen (陈德亮) is a Swedish climatologist, a pioneer in climate downscaling who held the August Röhss Chair at Gothenburg before joining Tsinghua University in 2024.
Deligne–Mumford stack
A Deligne–Mumford stack is an algebraic stack locally modeled on schemes by an étale surjective covering, introduced by Deligne and Mumford in 1969 for the moduli of algebraic curves.
Delphes
Delphes is a C++ framework for fast, parametric simulation of collider detector response, introduced in 2009 at Louvain and widely used for phenomenology and future-collider studies.
Delphinus
Delphinus, the Dolphin, is a small northern constellation near Altair, one of the 48 Greek constellations Ptolemy cataloged, whose diamond asterism is called Job's Coffin.
Delta baryon
Delta baryons are a family of excited non-strange baryons with isospin 3/2, the spin-3/2 partners of the nucleon; the Δ(1232) has four charge states and decays strongly to a nucleon and a pion.
Delta Cephei
Delta Cephei is a yellow supergiant star in Cepheus whose brightness varies between magnitudes 3.5 and 4.4 every 5.37 days, the prototype of the Cepheid variables.
Delta Delphini variable
A Delta Delphini variable is a chemically peculiar, evolved metallic-line A-type star that pulsates like a Delta Scuti star with a small light amplitude, named after Delta Delphini.
Delta Eridani
Delta Eridani, formally named Rana, is an orange subgiant star in the constellation Eridanus, about 29.5 light-years from the Sun and the constellation's fifth brightest star.
Delta learning
Delta learning, also known as Δ-learning, is a machine learning strategy in computational chemistry that trains models to correct fast baseline quantum chemical calculations to near target-method accuracy.
Delta method
The delta method is a statistical technique that uses a Taylor expansion to approximate the variance or limit distribution of a function of a random quantity.
Delta notation
Delta notation, also called the isotope delta, is the stable isotope geochemistry convention for reporting an isotope ratio as a relative difference from a reference material, in parts per mil.
Delta operator
A delta operator is a shift-invariant linear operator on polynomials that lowers degree by exactly one, central to Rota's finite operator calculus of binomial-type polynomial sequences.
Delta Ophiuchi
Delta Ophiuchi, also known as Yed Prior, is a red giant star of the constellation Ophiuchus, visible to the naked eye at magnitude 2.75, about 160 light-years from the Sun.
Delta Orionis
Delta Orionis (δ Orionis, Mintaka) is the westernmost star of Orion's Belt, a magnitude 2.4 multiple star system containing the nearest massive eclipsing binary, with an O-type pair orbiting every 5.7 days.
Delta Pavonis
Delta Pavonis (δ Pavonis) is a nearby G8 IV subgiant star in the southern constellation Pavo, about 19.92 light-years from Earth and visible to the naked eye.
Delta potential
The delta potential, also called the delta function potential, is an exactly solvable quantum mechanics model with potential V = ±αδ(x), zero except at one point.
Delta Scorpii
Delta Scorpii, also known as Dschubba, is a bright B-type star in the head of Scorpius about 400 light-years away, long considered stable until its major outburst in 2000.
Delta Scuti
A Delta Scuti (δ Sct) variable is a pulsating A- to F-type star near the main sequence, with short periods from about 15 minutes to 5 hours.