Large values of Hardy's Function from the Selberg class

Source abstract

Let $Z_F(t):=F(1/2+it) H(1/2+it)^{-1/2}$ denote Hardy's function, where the function $F(s)$ belongs to the Selberg class with polynomial Euler product and satisfies the functional equation $F(s)=H(s)\overline{F}(1-\bar{s})$. We prove that for every function of degree $1$ and for certain functions of degree $2$ belonging to the Selberg class, one has $$\begin{align*} \max_{T\leq t\leq 2T} \pm Z_F(t) &\gg \exp\left(C_F \sqrt{ \frac{\log T}{\log \log T} } \right), \end{align*}$$ where the constant $C_F$ depends on $F(s)$ and are explicitly determined.