The article shows how Libor interest rates can be described using a field theory model, with a common market measure emerging naturally. The researchers found that a martingale evolution can be chosen for Libor, ensuring each rate has the martingale property. They also explored different numeraire options for forward interest rates, showing that the price of an interest rate cap remains the same regardless of the numeraire used. Put-call parity was discussed, and the relationship between swaps, caps, and floors was briefly explored.