"infinity of possibilities" is correct and usable in written English.
You can use it to refer to a large number of possibilities or outcomes, particularly when the number is nearly impossible to count. For example: "With the rapid progress of technology, we are now presented with an infinity of possibilities for improving the lives of people around the world."
In fact, among students of literacy, the list is often seen as one of the main by-products of the invention of writing – and with lists come not so much an infinity of possibilities, but rule and orthodoxy.
Every frame has a lot going on; each image contains more than one image, no emotion is univocal, and every moment is alive with a seeming infinity of possibilities, including the worst.
I wanted to prove that far from being finished creatively and commercially, books still remained pregnant with an infinity of possibilities, that implicit in every book is the universe".
Saturday night contains an infinity of possibilities.
With this screenplay I wanted to make the viewer feel the abyss that is the infinity of possibilities.
The processor then moves through a near-infinity of possibilities to determine the lowest energy required to form those relationships.
Answering questions like these will be crucial if government planners are to determine which tactics, among a near-infinity of possibilities, should be adopted.
The critic Jean-François Rauger, at Le Monde, also praises the film's "perfection of digital special effects," which bring about "the feeling of a quasi-infinity of possibilities in graphic invention," and adds that the "playful exaltation of the adventurous man" reminds him of the flamboyant sword-and-shield action films directed by Riccardo Freda in the fifties and sixties.
Without human (or analogous, all-comprehensive, free beings), an infinity of ontological possibilities would not find their actualization.
