Black holes can emit heat. They have a temperature, entropy (a measure of disorder), and other thermodynamic properties. Usually, to compute these, you first have to construct the black hole itself — solve the complicated equations of curved spacetime. It's like figuring out the weight of a dish by cooking it from scratch every time.
In this work, a method previously proposed for a single special case is generalized to a whole class of objects — black branes. A brane is an extended object in a space with many dimensions. A one-dimensional brane resembles a string, a two-dimensional one a membrane. A black brane is a brane that possesses an event horizon, like a black hole. The authors show that the heat and entropy of such a brane can be found directly, bypassing the cumbersome construction of the solution. The method works for any number of dimensions and even for cases involving a scalar field (a field that varies from point to point but has no direction).
The practical benefit is speed. Previously, each new type of brane required a separate solution. Now you can immediately estimate how much heat it stores and how it will cool. This is important for theories where our world is a brane floating in a higher-dimensional space.
Black branes can be arbitrarily large in extent — theoretically, an entire universe could turn out to be the interior of such a brane.