Okay, so there is something called the Selberg trace formula. It's basically a fancy math thing that helps us understand how certain math objects are related to each other in a special way.
Imagine you have a group of friends, and you all have different jobs. One person is a doctor, another is a teacher, and so on. Now imagine you have a special way of connecting these jobs to each other - maybe the doctor helps the teacher with medical issues, and the teacher helps the lawyer with education-related issues. This is kind of like the Selberg trace formula. It helps us see how different parts of math are interconnected in a cool way.
The Selberg trace formula is based on something called "eigenvalues." Think of those as little pieces of information that tell you something important about a math object. It's like looking at the puzzle pieces of a picture and figuring out how they all fit together.
So with the Selberg trace formula, we can see how eigenvalues of one math object are related to eigenvalues of another math object. It's like figuring out how the puzzle pieces of two pictures fit together.
Now, this might all sound confusing, but it's actually really helpful for lots of things in math. We can use the Selberg trace formula to study symmetry groups, to understand how different shapes relate to each other, and even to study things like prime numbers (which are kind of like the special friends in our group from before).
Overall, the Selberg trace formula is a way of seeing how different parts of math are connected to each other. It's like a big puzzle, and we get to figure out how all the pieces fit together.