Some characterizations of BMO and Lipschitz spaces in the Schrödinger setting (2311.03407v1)

Abstract: We consider the Schr\"{o}dinger operator $\mathcal{L}=-\Delta+V$ on $\mathbb R^d$, $d\geq3$, where the nonnegative potential $V$ belongs to the reverse H\"{o}lder class $RH_s$ for some $s\geq d/2$. A real-valued function $f\in L^1_{\mathrm{loc}}(\mathbb R^d)$ belongs to the (BMO) space $\mathrm{BMO}{\rho,\theta}(\mathbb R^d)$ with $0<\theta<\infty$ if \begin{equation*} |f|{\mathrm{BMO}{\rho,\theta}} :=\sup{B(x_0,r)}\bigg(1+\frac{r}{\rho(x_0)}\bigg)^{-\theta}\bigg(\frac{1}{|B(x_0,r)|}\int_{B(x_0,r)}\big|f(x)-f_{B}\big|\,dx\bigg), \end{equation*} where the supremum is taken over all balls $B(x_0,r)\subset\mathbb R^d$, $\rho(\cdot)$ is the critical radius function in the Schr\"{o}dinger context and \begin{equation*} f_{B}:=\frac{1}{|B(x_0,r)|}\int_{B(x_0,r)}f(y)\,dy. \end{equation*} A real-valued function $f\in L^1_{\mathrm{loc}}(\mathbb R^d)$ belongs to the (Lipschitz) space $\mathrm{Lip}{\beta}^{\rho,\theta}(\mathbb R^d)$ with $0<\beta<1$ and $0<\theta<\infty$ if \begin{equation*} |f|{\mathrm{Lip}{\beta}^{\rho,\theta}} :=\sup{B(x_0,r)}\bigg(1+\frac{r}{\rho(x_0)}\bigg)^{-\theta} \bigg(\frac{1}{|B(x_0,r)|^{1+\beta/d}}\int_{B(x_0,r)}\big|f(x)-f_{B}\big|\,dx\bigg). \end{equation*} It can be easily seen that $\mathrm{BMO}{\rho,\theta}(\mathbb R^d)$ (or $\mathrm{Lip}{\beta}^{\rho,\theta}(\mathbb R^d)$) is a function space which is larger than the classical BMO (or Lipschitz) space. In this paper, we give some new characterizations of BMO and Lipschitz spaces associated with the Schr\"{o}dinger operator $\mathcal{L}$. We extend some previous works of Bongioanni--Harboure--Salinas and Liu--Sheng to the weighted case. The classes of weights considered here are larger than the classical Muckenhoupt classes.