ELI5: Explain Like I'm 5

Large deviations of Gaussian random functions

Okay, kiddo, so sometimes we look at things called functions. Think of a function like a machine that takes in a number and spits out another number.

Now, let's talk about something called a Gaussian random function. Gaussian just means that the function behaves like a bell curve, kind of like a round hill with a peak in the middle. And random means that the numbers the function spits out aren't predictable, they can be any number within a certain range.

So, when we talk about large deviations of a Gaussian random function, what we mean is that sometimes the function might spit out a number that is really far away from the middle peak of the bell curve. This is called a large deviation because it's a big difference from what we would normally expect the function to spit out based on the average behavior of the bell curve.

Now, why do we care about these large deviations? Well, sometimes they can tell us important things about the behavior of the system that the function is describing. For example, let's say the function is describing how stock prices change over time. If we see a large deviation, like a really big drop in stock prices, that could indicate that something unusual or unexpected happened in the stock market.

So, studying large deviations of Gaussian random functions is a way for scientists and mathematicians to better understand how different systems behave and to predict when unusual events might occur.