Bull. Korean Math. Soc. 2016; 53(1): 303-323
Printed January 1, 2016
https://doi.org/10.4134/BKMS.2016.53.1.303
Copyright © The Korean Mathematical Society.
Dong-Kwan Shin
Konkuk University
For a canonical threefold $X$, it is known that $p_n$ does not vanish for a sufficiently large $n$, where $p_n=h^0(X,{\mathcal O}_X(nK_X))$. We have shown that $p_n$ does not vanish for at least one $n$ in $\{6,\,8,\,10\}$. Assuming an additional condition $p_2\geq 1$ or $p_3\geq 1$, we have shown that $p_{12}\geq 2$ and $p_n\geq 2$ for $n\geq 14$ with one possible exceptional case. We have also found some inequalities between $\chi({\mathcal O}_X)$ and $K_X^3$.
Keywords: canonical threefold, threefold of general type, plurigenus
MSC numbers: 14J17, 14J30
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