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Segre Product
Segre may refer to: People * Segre (surname), people with the surname Segre or Segrè Places * Segre (river), a river in Catalonia, Spain ** Sègre (department), a former French department in Catalonia ** Sègre-Ter, a former French department in Catalonia ** Segre Olympic Park, a canoeing and kayaking facility in Catalonia, Spain ** Costers del Segre, a wine region in Catalonia, Spain ** Artesa de Segre, a municipality in Catalonia, Spain *** Tudela de Segre, a locality in Artesa de Segre, Catalonia, Spain ** Torres de Segre, a municipality in Catalonia, Spain ** Pic del Segre, a mountain between France and Spain ** Pic Petit de Segre, a mountain between France and Spain * Segré-en-Anjou Bleu, a commune in Maine-et-Loire, France ** Segré, a locality in Segré-en-Anjou Bleu, Maine-et-Loire, France ** Arrondissement of Segré, in Maine-et-Loire, France ** Canton of Segré-en-Anjou Bleu, in Maine-et-Loire, France * Segré, Burkina Faso Historical events * Battle of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre (surname)
Segre, Segrè or Segré is a Jewish-Italian surname, possibly tracing back to Sephardi communities from the area of the Segre River, Spain, or to the French town of Segré; it is concentrated in the areas of Turin, Milan and Rome. Notable people with the surname include: *Andrea Segre (born 1976), Italian film director *Beniamino Segre (1903–1977), Italian mathematician * Bruno Segre (1918–2024), Italian lawyer, journalist, politician and partisan * Cesare Segre (1928–2014), Italian philologist, semiotician and literary critic *Corrado Segre (1863–1924), Italian mathematician *Dino Segre (1893–1975), known as Pitigrilli, Italian journalist and novelist *Emilio Segrè (1905–1989), Italian-American chemist, physicist and Nobel laureate * Giacomo Segre (1839–1894), Italian military officer *Gino Segrè (born 1938), Italian-American physicist and academic * (1881–1945), Jewish Italian entrepreneur and member of the Fascist Party * Jacopo Segre (born 1997), Italian footba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segré, Burkina Faso
Segré is a village in the Diébougou Department of Bougouriba Province in south-western Burkina Faso Burkina Faso is a landlocked country in West Africa, bordered by Mali to the northwest, Niger to the northeast, Benin to the southeast, Togo and Ghana to the south, and Ivory Coast to the southwest. It covers an area of 274,223 km2 (105,87 .... The village has a population of 592. References Populated places in the Sud-Ouest Region (Burkina Faso) Bougouriba Province {{Bougouriba-geo-stub ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeuthen–Segre Invariant
In algebraic geometry, the Zeuthen–Segre invariant ''I'' is an invariant of a projective surface found in a complex projective space which was introduced by and rediscovered by . The invariant ''I'' is defined to be ''d'' – 4''g'' – ''b'' if the surface has a pencil of curves, non-singular of genus ''g'' except for ''d'' curves with 1 ordinary node In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines ..., and with ''b'' base points where the curves are non-singular and transverse. showed that the Zeuthen–Segre invariant ''I'' is χ–4, where χ is the topological Euler–Poincaré characteristic introduced by , which is equal to the Chern number ''c''2 of the surface. References * * Reprinted 2010 * * * * Algebraic surfaces {{algebraic-geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segrè–Silberberg Effect
The Segrè–Silberberg effect is a fluid dynamic In physics, physical chemistry and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids – liquids and gases. It has several subdisciplines, including (the study of air and other gases in motio ... Separation process, separation effect where a dilute suspension of neutrally buoyant particles flowing (in laminar flow) in a tube equilibrates at a distance of 0.6''R'' from the tube's centre. This effect was first observed by Gino Segrè and Alexander Silberberg in 1961. The solid particles are subjected to both viscous Drag (physics), drag forces and inertial lift forces. The drag forces are responsible for driving particles along the flow streamlines, whereas the inertial forces are responsible for the lateral migration of particles across the flow streamlines. The parabolic nature of the laminar velocity profile in Hagen–Poiseuille equation, Poiseuille flow produces a shear-induc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre's Theorem
In projective geometry, Segre's theorem, named after the Italian mathematician Beniamino Segre, is the statement: *Any Oval (projective plane), oval in a ''finite Pappus's hexagon theorem, pappian'' projective plane of ''odd'' order is a nondegenerate projective conic section. This statement was assumed 1949 by the two Finnish mathematicians Gustaf Järnefelt, G. Järnefelt and Paul Kustaanheimo, P. Kustaanheimo and its proof was published in 1955 by B. Segre. A finite pappian projective plane can be imagined as the projective closure of the real plane (by a line at infinity), where the real numbers are replaced by a finite field . ''Odd order'' means that is odd. An oval is a curve similar to a circle (see definition below): any line meets it in at most 2 points and through any point of it there is exactly one tangent. The standard examples are the nondegenerate projective conic sections. In pappian projective planes of ''even'' order greater than four there are ovals which are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre Surface
In algebraic geometry, a Segre surface, studied by and , is an intersection of two quadrics in 4-dimensional projective space. They are rational surfaces isomorphic to a projective plane blown up in 5 points with no 3 on a line, and are del Pezzo surface In mathematics, a del Pezzo surface or Fano surface is a two-dimensional Fano variety, in other words a non-singular projective algebraic surface with ample anticanonical divisor class. They are in some sense the opposite of surfaces of genera ...s of degree 4, and have 16 rational lines. The term "Segre surface" is also occasionally used for various other surfaces, such as a quadric in 3-dimensional projective space, or the hypersurface :x_1 x_2 x_3 + x_2 x_3 x_4 + x_3 x_4 x_5 + x_4 x_5 x_1 + x_5 x_1 x_2 = 0. \, References * *{{Citation , doi=10.1093/qmath/2.1.216 , last1=Segre , first1=Beniamino , title=On the inflexional curve of an algebraic surface in S4 , mr=0044861 , year=1951 , journal=The Quarterly Journal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre Embedding
In mathematics, the Segre embedding is used in projective geometry to consider the cartesian product (of sets) of two projective spaces as a projective variety. It is named after Corrado Segre. Definition The Segre map may be defined as the map :\sigma: P^n \times P^m \to P^\ taking a pair of points ( \in P^n \times P^m to their product :\sigma:( _0:X_1:\cdots:X_n _0:Y_1:\cdots:Y_m \mapsto _0Y_0: X_0Y_1: \cdots :X_iY_j: \cdots :X_nY_m (the ''XiYj'' are taken in lexicographical order). Here, P^n and P^m are projective vector spaces over some arbitrary field, and the notation : _0:X_1:\cdots:X_n is that of homogeneous coordinates on the space. The image of the map is a variety, called a Segre variety. It is sometimes written as \Sigma_. Discussion In the language of linear algebra, for given vector spaces ''U'' and ''V'' over the same field ''K'', there is a natural way to linearly map their Cartesian product to their tensor product. : \varphi: U\times V \to U\otim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre Cubic
In algebraic geometry, the Segre cubic is a cubic threefold embedded in 4 (or sometimes 5) dimensional projective space, studied by . Definition The Segre cubic is the set of points (''x''0:''x''1:''x''2:''x''3:''x''4:''x''5) of ''P''5 satisfying the equations :\displaystyle x_0+x_1+x_2+x_3+x_4+x_5= 0 :\displaystyle x_0^3+x_1^3+x_2^3+x_3^3+x_4^3+x_5^3 = 0. Properties The intersection of the Segre cubic with any hyperplane ''x''''i'' = 0 is the Clebsch cubic surface. Its intersection with any hyperplane ''x''''i'' = ''x''''j'' is Cayley's nodal cubic surface. Its dual is the Igusa quartic 3-fold in P4. Its Hessian is the Barth–Nieto quintic. A cubic hypersurface in ''P''4 has at most 10 nodes, and up to isomorphism the Segre cubic is the unique one with 10 nodes. Its nodes are the points conjugate to (1:1:1:−1:−1:−1) under permutations of coordinates. The Segre cubic is rational Rationality is the quality of being guided by or based on reason. In thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre Classification
The Segre classification is an algebraic classification of rank two symmetric tensors. It was proposed by the italian mathematician Corrado Segre in 1884. The resulting types are then known as Segre types. It is most commonly applied to the energy–momentum tensor (or the Ricci tensor) and primarily finds application in the classification of exact solutions in general relativity. See also *Corrado Segre *Jordan normal form \begin \lambda_1 1\hphantom\hphantom\\ \hphantom\lambda_1 1\hphantom\\ \hphantom\lambda_1\hphantom\\ \hphantom\lambda_2 1\hphantom\hphantom\\ \hphantom\hphantom\lambda_2\hphantom\\ \hphantom\lambda_3\hphantom\\ \hphantom\ddots\hphantom\\ ... * Petrov classification References * See ''section 5.1'' for the Segre classification. * Linear algebra Tensors Tensors in general relativity {{math-physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segre Class
In mathematics, the Segre class is a characteristic class used in the study of cones, a generalization of vector bundles. For vector bundles the total Segre class is inverse to the total Chern class, and thus provides equivalent information; the advantage of the Segre class is that it generalizes to more general cones, while the Chern class does not. The Segre class was introduced in the non-singular case by Beniamino Segre (1953). In the modern treatment of intersection theory in algebraic geometry, as developed e.g. in the definitive book of Fulton (1998), Segre classes play a fundamental role. Definition Suppose C is a cone over X , q is the projection from the projective completion \mathbb(C \oplus 1) of C to X, and \mathcal(1) is the anti-tautological line bundle on \mathbb(C \oplus 1). Viewing the Chern class c_1(\mathcal(1)) as a group endomorphism of the Chow group of \mathbb(C \oplus 1), the total Segre class of C is given by: :s(C) = q_* \left( \sum_ c_1(\mathcal(1)) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segrè Chart
A table or chart of nuclides is a two-dimensional graph of isotopes of the chemical elements, in which one axis represents the number of neutrons (symbol ''N'') and the other represents the number of protons (atomic number, symbol ''Z'') in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical element. This system of ordering nuclides can offer a greater insight into the characteristics of isotopes than the better-known periodic table, which shows only elements and not their isotopes. The chart of the nuclides is also known as the Segrè chart, after Italian physicist Emilio Segrè. Description and utility A chart or table of nuclides maps the nuclear, or radioactive, behavior of nuclides, as it distinguishes the isotopes of an element. It contrasts with a periodic table, which only maps their chemical behavior, since isotopes (nuclides that are variants of the same element) do not differ chemically to any significant degre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battle Of Segré
The Battle of Segré was a battle between the forces of Conan II, Duke of Brittany, and an alliance of the rebel Rivallon I of Dol, the Angevin Empire, and the Duchy of Normandy, fought as part of the Breton–Norman War. During Conan's 1066 campaign against Anjou, he took Segré Segré () is a former commune in the Maine-et-Loire department in western France. On 15 December 2016, it was merged into the new commune Segré-en-Anjou Bleu. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
