Quantum gravity has a natural cutoff given by the Planck scale. However, the EFT of quantum gravity can break down at a lower scale known as the species scale, which is when higher-curvature corrections become important. Additionally, there is a third scale which marks the inverse length (or the temperature) of the smallest black hole where the EFT gives a correct description of its entropy and free energy. Understanding the distinction and interplay among these three scales can shed light on fundamental aspects of quantum gravity and have important applications to phenomenology. In this talk, I will introduce the species scale as a moduli-dependent quantity in supersymmetric theories and motivate the existence of the black hole scale in quantum gravity. At last, I will provide evidence for two global bounds of the species scale and the black hole scale over the moduli space of quantum gravity.
Bio:
David Wu completed his undergraduate studies at Caltech and is currently a third year PhD student in the Center of Fundamental Laws in the department of physics at Harvard University under the supervision of Prof. Cumrun Vafa. He is mostly interested in the swampland program of quantum gravity.
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Prof. Yinan Wang