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The rational filling radius of complex projective space. (English) Zbl 0749.53032
In this paper the author computes the filling radius with rational coefficients of the complex projective $$n$$-space as $${1\over 2} \arccos(- {1\over 3})$$ by a straightforward homological calculation using the Serre-spectral sequence and the Schubert calculus. He also computes the integer filling radius of the complex projective 2-space as $${1\over 2}\arccos(-{1\over 3})$$ again and exhibits a torsion obstruction to filling complex projective 3-space.

##### MSC:
 53C35 Differential geometry of symmetric spaces 53C55 Global differential geometry of Hermitian and Kählerian manifolds 14M15 Grassmannians, Schubert varieties, flag manifolds
##### Keywords:
Serre-spectral sequence; Schubert calculus; filling radius
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##### References:
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