When n=1, the formula becomes . According to the Hodge theorem, . Consequently , where g is the usual (topological) meaning of genus of a surface, so the definitions are compatible.
When X is a compact Kähler manifold, applying hp,q = hq,p recovers the earlier definition for projective varieties.
Rubei, Elena (2014), Algebraic Geometry, a concise dictionary, Berlin/Boston: Walter De Gruyter, ISBN978-3-11-031622-3
^Hartshorne, Robin (1977). Algebraic Geometry. Graduate Texts in Mathematics. Vol. 52. New York, NY: Springer New York. p. 230. doi:10.1007/978-1-4757-3849-0. ISBN978-1-4419-2807-8. S2CID 197660097.
Further reading
Hirzebruch, Friedrich (1995) [1978]. Topological methods in algebraic geometry. Classics in Mathematics. Translation from the German and appendix one by R. L. E. Schwarzenberger. Appendix two by A. Borel (Reprint of the 2nd, corr. print. of the 3rd ed.). Berlin: Springer-Verlag. ISBN3-540-58663-6. Zbl 0843.14009.
May 16, 2023
arithmetic, genus, mathematics, arithmetic, genus, algebraic, variety, possible, generalizations, genus, algebraic, curve, riemann, surface, contents, projective, varieties, complex, projective, manifolds, kähler, manifolds, also, references, further, readingp. In mathematics the arithmetic genus of an algebraic variety is one of a few possible generalizations of the genus of an algebraic curve or Riemann surface Contents 1 Projective varieties 2 Complex projective manifolds 3 Kahler manifolds 4 See also 5 References 6 Further readingProjective varieties EditLet X be a projective scheme of dimension r over a field k the arithmetic genus p a displaystyle p a of X is defined asp a X 1 r x O X 1 displaystyle p a X 1 r chi mathcal O X 1 Here x O X displaystyle chi mathcal O X is the Euler characteristic of the structure sheaf O X displaystyle mathcal O X 1 Complex projective manifolds EditThe arithmetic genus of a complex projective manifold of dimension n can be defined as a combination of Hodge numbers namely p a j 0 n 1 1 j h n j 0 displaystyle p a sum j 0 n 1 1 j h n j 0 When n 1 the formula becomes p a h 1 0 displaystyle p a h 1 0 According to the Hodge theorem h 0 1 h 1 0 displaystyle h 0 1 h 1 0 Consequently h 0 1 h 1 X 2 g displaystyle h 0 1 h 1 X 2 g where g is the usual topological meaning of genus of a surface so the definitions are compatible When X is a compact Kahler manifold applying hp q hq p recovers the earlier definition for projective varieties Kahler manifolds EditBy using hp q hq p for compact Kahler manifolds this can be reformulated as the Euler characteristic in coherent cohomology for the structure sheaf O M displaystyle mathcal O M p a 1 n x O M 1 displaystyle p a 1 n chi mathcal O M 1 This definition therefore can be applied to some other locally ringed spaces See also EditGenus mathematics Geometric genusReferences EditP Griffiths J Harris 1994 Principles of Algebraic Geometry Wiley Classics Library 2nd ed Wiley Interscience p 494 ISBN 0 471 05059 8 Zbl 0836 14001 Rubei Elena 2014 Algebraic Geometry a concise dictionary Berlin Boston Walter De Gruyter ISBN 978 3 11 031622 3 Hartshorne Robin 1977 Algebraic Geometry Graduate Texts in Mathematics Vol 52 New York NY Springer New York p 230 doi 10 1007 978 1 4757 3849 0 ISBN 978 1 4419 2807 8 S2CID 197660097 Further reading EditHirzebruch Friedrich 1995 1978 Topological methods in algebraic geometry Classics in Mathematics Translation from the German and appendix one by R L E Schwarzenberger Appendix two by A Borel Reprint of the 2nd corr print of the 3rd ed Berlin Springer Verlag ISBN 3 540 58663 6 Zbl 0843 14009 Retrieved from https en wikipedia org w index php title Arithmetic genus amp oldid 1138471919, wikipedia, wiki, book, books, library,