ELI5: Explain Like I'm 5

Rogers–Ramanujan identities

Imagine you are playing a game of counting with your friends. You start by counting from 1 to 10, and then your friend starts counting from 1 to 10. But instead of stopping there, you start over and count from 1 to 10 again, repeating this pattern for a few more rounds.

Now imagine that instead of counting, you are adding up numbers. You start by adding up all the numbers from 1 to 10, and then your friend does the same. But then you start over and add up all the numbers from 1 to 10 again, repeating this pattern a few more times.

The Rogers-Ramanujan identities are equations that describe how you can add up numbers in this pattern infinitely many times. Specifically, they tell you how to calculate the sum of certain sequences of numbers that repeat in this way.

These identities were discovered by two mathematicians named Leonard Rogers and Srinivasa Ramanujan in the early 20th century. They were interested in understanding the patterns that emerge when you add up certain types of infinite series.

The equations they discovered are quite complex, but they have important applications in many areas of mathematics and physics. They have been used to study topics such as partitions of integers, elliptic functions, and superstring theory.

So, in a nutshell, the Rogers-Ramanujan identities are equations that describe how to add up certain sequences of numbers that repeat in a specific pattern, and they have many interesting applications in mathematics and physics.