Weyl Invariance

Weyl invariance is a symmetry in physics where the laws remain unchanged if the sizes of all distances and fields are scaled uniformly. Imagine measuring lengths with different rulers; if the physics doesn't change when you rescale all measurements proportionally, it's Weyl invariant. This concept is important in understanding how certain theories, especially in high-energy physics and gravitation, behave under scale transformations, helping to explore the fundamental structure of spacetime and the nature of physical laws at different scales.