All articles starting with D
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Dirhodium-catalyzed enantioselective C–H amination
A reaction in which a chiral dirhodium(II) catalyst converts an organic molecule's carbon–hydrogen bond into a carbon–nitrogen bond, creating a stereocenter with preference for one enantiomer.
Dirichlet algebra
A Dirichlet algebra is a uniform algebra of continuous functions on a compact space whose real parts are dense in all real continuous functions, defined by Gleason in 1958.
Dirichlet boundary condition
The Dirichlet boundary condition, also known as the first-type or fixed boundary condition, requires a partial differential equation's solution to equal given values on the domain's boundary.
Dirichlet character
A Dirichlet character modulo q is a completely multiplicative, periodic function vanishing on integers not coprime to q, central to Dirichlet's 1837 theorem on primes in arithmetic progressions.
Dirichlet conditions
The Dirichlet conditions are sufficient conditions on a periodic function, including absolute integrability over one period, guaranteeing pointwise convergence of its Fourier series, first proved by Dirichlet in 1829.
Dirichlet convolution
Dirichlet convolution is a binary operation on arithmetic functions, combining two functions by summing f(d)g(n/d) over divisor pairs of n, named after the German mathematician Dirichlet.
Dirichlet distribution
The Dirichlet distribution is a continuous multivariate probability distribution over vectors of proportions summing to one, generalizing the beta distribution and serving as the conjugate prior to the multinomial distribution.
Dirichlet divisor problem
The Dirichlet divisor problem in number theory seeks the smallest exponent bounding the error term in the asymptotic formula for the summatory divisor function, conjectured to be 1/4.
Dirichlet eta function
The Dirichlet eta function, also called the alternating zeta function, is defined by the series 1 − 2−s + 3−s − ⋯, convergent for Re(s) > 0.
Dirichlet form
A Dirichlet form is a closed, symmetric, Markovian quadratic form on an L²-space, introduced by Beurling and Deny, linking potential theory to symmetric Markov processes.
Dirichlet integral
The Dirichlet integral is the improper integral of sin x over x from 0 to infinity, equal to π/2, named after Peter Gustav Lejeune Dirichlet.
Dirichlet L-function
A Dirichlet L-function (Dirichlet L-series) is a meromorphic function L(s, χ) defined by a Dirichlet character, introduced in 1837 to prove Dirichlet's theorem on primes in arithmetic progressions.
Dirichlet problem
The Dirichlet problem is the potential-theory problem of finding a function harmonic in a domain, satisfying the Laplace equation, that takes prescribed values on the domain's boundary.
Dirichlet process
The Dirichlet process is a stochastic process whose realizations are random probability distributions, used as a prior over unknown distributions, introduced by Thomas Ferguson in 1973.
Dirichlet process mixture model
A Dirichlet process mixture model is a Bayesian mixture model whose mixing distribution is random, allowing the number of components to be inferred from data.
Dirichlet series
A Dirichlet series is an infinite series of the form of a sum of coefficients divided by n to the power s, with s a complex variable.
Dirichlet space
The Dirichlet space is the Hilbert space of functions analytic on the open unit disk whose Dirichlet integral is finite, one of the three classical Hilbert spaces of holomorphic functions.
Dirichlet-multinomial distribution
The Dirichlet-multinomial distribution, also known as the multivariate Pólya distribution, is a probability distribution for count vectors whose category probabilities are drawn from a Dirichlet distribution.
Dirichlet's theorem on arithmetic progressions
Dirichlet's theorem on arithmetic progressions, or Dirichlet's theorem on primes, states that for coprime integers a and q, infinitely many primes satisfy p ≡ a (mod q), proved in 1837.
Dirigisme
Dirigisme, or a dirigiste economy, is an economic doctrine in which the state steers a market economy toward chosen goals through indicative planning and directed credit, its archetype postwar France between 1946 and the mid-1970s.
Diriliş
Diriliş was a Turkish thought, literature, and politics magazine founded, led, and largely written by the poet Sezai Karakoç, published with interruptions from 1960 to 1992.
Diriliş: Ertuğrul
Diriliş: Ertuğrul (Resurrection: Ertuğrul) is a Turkish historical drama (2014–2019, TRT 1, 150 episodes, five seasons) about Ertuğrul Gazi and the Kayı tribe, produced by Mehmet Bozdağ, exported to 71 countries, and succeeded by Kuruluş: Osman.
Diris
Diris (Dris, Sidere, Si-perde, Sipere, Si-perek) is a three-in-a-row alignment board game played in Persia in the seventeenth century, recorded by Hyde (1694) and Murray (1951), with a board of three consecutive squares.
Dirithromycin
Dirithromycin (Dynabac, LY 237216) is a once-daily macrolide antibiotic prodrug hydrolyzed to erythromycylamine; half-life 44 h, FDA approved 1995, used for respiratory and skin infections.
Diriyah
Diriyah (الدرعية) is a historic town northwest of Riyadh, Saudi Arabia, first capital of the Saudi dynasty and seat of the First Saudi State from 1727 to 1818.
Dirk
A dirk is a long dagger, originally the heavy thrusting knife carried by the Highlanders of Scotland and later the straight-bladed sidearm worn by naval officers in the 18th and 19th centuries.
Dirk Benedict
Dirk Benedict (born Dirk Niewoehner, 1945, Montana) is an American actor known as Lieutenant Starbuck in Battlestar Galactica (1978–79) and Templeton "Faceman" Peck in The A-Team (1983–87), also a stage actor, director, and author.
Dirk Bergemann
Dirk Bergemann is a German and American economist who holds the Douglass and Marion Campbell Professorship of Economics at Yale University and helped found information design.
Dirk Blocker
Dirk Blocker (born 1957, Hollywood) is an American character actor, son of Bonanza star Dan Blocker, best known as Detective Michael Hitchcock on Brooklyn Nine-Nine (2013-2021, 153 episodes), with film roles in Poltergeist, Starman, and Short Cuts.
Dirk Bogarde
Dirk Bogarde (Derek Jules Gaspard Ulric Niven van den Bogaerde, 1921–1999), English actor and writer: 1950s Rank matinee idol, star of Victim, The Servant, Death in Venice; twice BAFTA Best Actor, knighted 1992, memoirist and novelist.