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Let $X$ be a smooth, complex projective algebraic variety defined over a number field $K$. Let $D$ be a divisor of $X$ defined over $K$ with the following property:

For any curve $C$ defined over $K$, we have $\operatorname{deg (D_{|C})=0}$

Is it then true that $c_1(D)=0$?

In general, in order to have $c_1(D)=0$  ,I I should check that $\operatorname{deg (D_{|C})=0}$ for any curve (not just the ones defined over $K$). I'm asking if in this particular setting, the curves defined over $K$ are enough.

Let $X$ be a smooth, complex projective algebraic variety defined over a number field $K$. Let $D$ be a divisor of $X$ defined over $K$ with the following property:

For any curve $C$ defined over $K$, we have $\operatorname{deg (D_{|C})=0}$

Is it then true that $c_1(D)=0$?

In general, in order to have $c_1(D)=0$  ,I should check that $\operatorname{deg (D_{|C})=0}$ for any curve (not just the ones defined over $K$). I'm asking if in this particular setting, the curves defined over $K$ are enough.

Let $X$ be a smooth, complex projective algebraic variety defined over a number field $K$. Let $D$ be a divisor of $X$ defined over $K$ with the following property:

For any curve $C$ defined over $K$, we have $\operatorname{deg (D_{|C})=0}$

Is it then true that $c_1(D)=0$?

In general, in order to have $c_1(D)=0$, I should check that $\operatorname{deg (D_{|C})=0}$ for any curve (not just the ones defined over $K$). I'm asking if in this particular setting, the curves defined over $K$ are enough.

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manifold
manifold
  • 321
  • 6
  • 15

First Chern class and field extensions

Let $X$ be a smooth, complex projective algebraic variety defined over a number field $K$. Let $D$ be a divisor of $X$ defined over $K$ with the following property:

For any curve $C$ defined over $K$, we have $\operatorname{deg (D_{|C})=0}$

Is it then true that $c_1(D)=0$?

In general, in order to have $c_1(D)=0$ ,I should check that $\operatorname{deg (D_{|C})=0}$ for any curve (not just the ones defined over $K$). I'm asking if in this particular setting, the curves defined over $K$ are enough.