# A new second order upper bound for the ground state energy of dilute Bose gases

### Giulia Basti, Serena Cenatiempo, Benjamin Schlein

Giulia Basti, Serena Cenatiempo, Benjamin Schlein

**21/1/21**Published in : arXiv:2101.06222

We establish an upper bound for the ground state energy per unit volume of a dilute Bose gas in the thermodynamic limit, capturing the correct second order term, as predicted by the Lee-Huang-Yang formula. This result has been first established in J. Stat. Phys. 136(3) by H.-T. Yau and J. Yin. Our proof, which applies to repulsive and compactly supported V \in L^3 (\mathbb{R}^3), gives better rates and, in our opinion, is substantially simpler.