In Riemannian geometry the positivity non-negativity of the Ricci curvature $R$ of a manifold $X$ has strong implications on the size of the fundamental group $\pi_1(X)$:

1. If $R>0$, then $\pi_1(X)$ is finite.
2. If $R=0$, it is known that $\pi_1(X)$ is almost abelian, i.e., it contains an abelian subgroup of finite index.

In both these casesAlso, $\pi_1(X)$ has 'polynomial growth'growth.

In the case $X$ is a smooth complex projective variety, the positivity of Ricci curvature is related to ampleness properties of of $-K_X$. -K_X$, so it would be interesting to see whether analogous results of the above hold in algebraic geometry, with Ricci curvature replaced by the Kodaira dimension$\kappa(X)=\sup_n\dim\phi_{nK}(X)$. So my question iswhether : What implications do non-positive Kodaira dimension have for the fundamental group of$X$? In particular, does some versions of the above results hold in algebraic geometry, with Ricci curvature replaced by Kodaira dimension$\kappa(X)=\sup_n \dim\phi_{nK}(X)$. ? For example, if$X$is a smooth projective variety with$\kappa(X)=0$, is$\pi_1(X)$almost abelian? One could also ask for refined versions of the above statements. For example, when$X$is Fano it is well-known that$\pi_1(X)=0$. Does the same condition hold for all$X$with big$-K_X$? 2 added 21 characters in body In Riemannian geometry the positivity of the Ricci curvature$R$of a manifold$M$X$ has strong implications on the size of the fundamental group $\pi_1(M)$: \pi_1(X)$: 1. If$R>0$, then$\pi_1(M)$\pi_1(X)$ is finite.
2. If $R=0$, it is known that $\pi_1(M)$ \pi_1(X)$is almost abelian, i.e., it contains an abelian subgroup of finite index. In both these cases,$\pi_1(M)$\pi_1(X)$ has 'polynomial growth'.

On

In the case $X$ is a smooth complex projective variety$X$, positive , the positivity of Ricci curvature is related to ampleness properties of of $-K_X$. So my question is whether some versions of the above results hold in algebraic geometry, with Ricci curvature replaced by Kodaira dimension $\kappa(X)=\sup_n \dim\phi_{nK}(X)$. For example, if $X$ is a smooth projective variety with $\kappa(X)=0$, is $\pi_1(X)$ almost abelian?

One could also ask for refined versions of the above statements. For example, when $X$ is Fano it is well-known that $\pi_1(X)=0$. Does the same condition hold for all $X$ with big $-K_X$?

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# Kodaira dimension and fundamental groups

In Riemannian geometry the positivity of the Ricci curvature $R$ of a manifold $M$ has strong implications on the size of the fundamental group $\pi_1(M)$:

1. If $R>0$, then $\pi_1(M)$ is finite.
2. If $R=0$, it is known that $\pi_1(M)$ is almost abelian, i.e., it contains an abelian subgroup of finite index.

In both these cases, $\pi_1(M)$ has 'polynomial growth'.

On a smooth complex projective variety $X$, positive Ricci curvature is related to ampleness properties of of $-K_X$. So my question is whether some versions of the above results hold in algebraic geometry, with Ricci curvature replaced by Kodaira dimension $\kappa(X)=\sup_n \dim\phi_{nK}(X)$. For example, if $X$ is a smooth projective variety with $\kappa(X)=0$, is $\pi_1(X)$ almost abelian?

One could also ask for refined versions of the above statements. For example, when $X$ is Fano it is well-known that $\pi_1(X)=0$. Does the same condition hold for all $X$ with big $-K_X$?