On the Euler characteristic of a relative hypersurface
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On the Euler characteristic of a relative hypersurface. / Fullwood, James; Helmer, Martin.
I: Journal of Mathematical Physics, Bind 60, Nr. 5, 052302, 2019.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - On the Euler characteristic of a relative hypersurface
AU - Fullwood, James
AU - Helmer, Martin
PY - 2019
Y1 - 2019
N2 - We derive a general formula for the Euler characteristic of a fibration of projective hypersurfaces in terms of invariants of an arbitrary base variety. When the general fiber is an elliptic curve, such formulas have appeared in the physics literature in the context of calculating D-brane charge for M-/F-theory and type-IIB compactifications of string vacua. While there are various methods for computing Euler characteristics of algebraic varieties, we prove a base-independent pushforward formula which reduces the computation of the Euler characteristic of relative hypersurfaces to simple algebraic manipulations of rational expressions determined by its divisor class in a projective bundle. We illustrate our methods by applying them to an explicit family of relative hypersurfaces whose fibers are of arbitrary dimension and degree.
AB - We derive a general formula for the Euler characteristic of a fibration of projective hypersurfaces in terms of invariants of an arbitrary base variety. When the general fiber is an elliptic curve, such formulas have appeared in the physics literature in the context of calculating D-brane charge for M-/F-theory and type-IIB compactifications of string vacua. While there are various methods for computing Euler characteristics of algebraic varieties, we prove a base-independent pushforward formula which reduces the computation of the Euler characteristic of relative hypersurfaces to simple algebraic manipulations of rational expressions determined by its divisor class in a projective bundle. We illustrate our methods by applying them to an explicit family of relative hypersurfaces whose fibers are of arbitrary dimension and degree.
UR - http://www.scopus.com/inward/record.url?scp=85065797800&partnerID=8YFLogxK
U2 - 10.1063/1.5030475
DO - 10.1063/1.5030475
M3 - Journal article
AN - SCOPUS:85065797800
VL - 60
JO - Journal of Mathematical Physics
JF - Journal of Mathematical Physics
SN - 0022-2488
IS - 5
M1 - 052302
ER -
ID: 222754132