There is not enough evidence to even conclude that magnetic monopoles exist at all in this universe.

The existence of magnetic monopoles has long been an interesting and profound possibility.

If you should ever find such a thing, you will have discovered a "magnetic monopole".

This is the mathematical way of saying: "There are no magnetic monopoles".

Despite these efforts, no magnetic monopole has been observed to date.

A number of attempts have been made to detect magnetic monopoles.

It is equivalent to the statement that magnetic monopoles do not exist.

So far no magnetic monopoles have been found, despite extensive search.

This transition should produce magnetic monopoles in large quantities, which are not observed.

The detection of magnetic monopoles is an open problem in experimental physics.