# Existence and mass concentration of pseudo-relativistic Hartree equation

## TL;DR

This paper studies the existence and properties of minimizers for a pseudo-relativistic Hartree energy functional, identifying a critical parameter value where minimizers cease to exist and analyzing their behavior near this threshold.

## Contribution

It establishes the existence threshold for minimizers of the pseudo-relativistic Hartree energy and examines their asymptotic behavior as the parameter approaches this critical value.

## Key findings

- Existence of a critical threshold a* for minimizers.
- No minimizers exist when a ≥ a*.
- Asymptotic behavior of minimizers as a approaches a*.

## Abstract

In this paper, we investigate the constrained minimization problem \begin{equation}\label{eq:0.1} e(a):=\inf_{\{u\in \mathcal{H},\|u\|_2^2=1\}}E_a(u), \end{equation} where the energy functional \begin{equation} \label{eq:0.2} E_a(u)=\int_{\mathbb{R}^3}(u\sqrt{-\Delta+m^2}\,u+Vu^2)\,dx -\frac{a}{2}\int_{\mathbb{R}^3}(|x|^{-1}*u^2)u^2\,dx \end{equation} with $m\in \mathbb{R}$, $a>0$, is defined on a Sobolev space $\mathcal{H}$. We show that there exists a threshold $a^*>0$ so that $e(a)$ is achieved if $0<a<a^*$, and has no minimizers if $a\geq a^*$. We also investigate the asymptotic behavior of nonnegative minimizers of $e(a)$ as $a\to a^*$.