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Mridul Biswas

Publications and source records attributed to Mridul Biswas.

2 recordsLinked to original sources
arXiv2026

On the Vanishing of the Brauer-Manin Obstruction for Normic Bundles

We study the behaviour of the Brauer--Manin obstruction to the existence of rational points under finite field extensions. For $(p, mp)$-normic bundles over number fields, we prove that the Brauer--Manin obstruction vanishes after base change to finite extensions whose degrees satisfy suitable $p$-divisibility conditions depending on $m$. We further show that, for $(p,2p)$-normic bundles with $p=2$ or $3$, it is enough to assume that the extension degree is divisible by $p$. We also prove that the divisibility hypothesis is, in general optimal, by constructing a conic bundle for which the Brauer--Manin obstruction persists over a quadratic extension.

math.NT↗
arXiv2026

Pullback Method with Applications to Severi--Brauer Fibrations

Given a variety with a suitable Brauer class, we present a general pullback construction that produces varieties that has Brauer--Manin obstruction to the existence of rational points. We then study Severi--Brauer fibrations and their Brauer groups without relying on explicit defining equations. As a key application, we show that there exist Severi--Brauer fibrations with index one that fails Hasse principle.

math.NT↗