On q-Runge pairs
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 5, Tome 2 (2003) no. 2, pp. 231-235.

We show that the converse of the aproximation theorem of Andreotti and Grauert does not hold. More precisely we construct a 4-complete open subset D⊂ℂ6 (which is an analytic complement in the unit ball) such that the restriction map H3(ℂ6,ℱ)→H3(D,ℱ) has a dense image for every ℱ∈Coh(ℂ6) but the pair (D,ℂ6) is not a 4-Runge pair.

Classification : 32F10, 32F27, 32E30 
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     title = {On $q${-Runge} pairs},
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     volume = {Ser. 5, 2},
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Colţoiu, Mihnea. On $q$-Runge pairs. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Série 5, Tome 2 (2003) no. 2, pp. 231-235. https://numdam.org/item/ASNSP_2003_5_2_2_231_0/

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