Causality in Quantum Field Theory

In quantum field theory, causality ensures that events or signals cannot influence each other faster than the speed of light. This means that cause-and-effect relationships are preserved so that an action at one point in space and time cannot instantaneously affect another distant point. Mathematically, this is reflected in how fields and particles behave, maintaining consistent order of events and respecting the limit set by relativity. In simple terms, causality in quantum fields guarantees that information doesn't travel faster than light, preserving the logical structure of cause and effect in the universe.