Species Entropy and Thermodynamics

Understand

We analyse particle species and the species scale in quantum gravity from a thermodynamic perspective.

• In close analogy to black hole thermodynamics, we propose that particle species own an entropy and a temperature, which is determined by the species scale.
• This is identical to the Bekenstein-Hawking entropy of a corresponding minimal black hole and agrees with the number of species in a given tower of states.
• Through the species entropy, we find that certain entropy bounds are connected to recent swampland constraints.