simclr.tex

\documentclass[tikz,border=2pt]{standalone}
\usepackage{amsmath,bm}
\usepackage{tikz}
% \usetikzlibrary{arrows.meta}  % if you need extra arrowheads
\begin{document}
\begin{tikzpicture}
    \node at (0,1.8) (h) {$\longleftarrow\,$Representation$\,\longrightarrow$};
    \node[draw, circle] at (0,-1) (x) {$\bm{x}$};
    \node[draw, circle] at (-2.5,0) (x1) {$\tilde{\bm{x}}_i$};
    \node[draw, circle] at (2.5,0) (x2) {$\tilde{\bm{x}}_j$};
    \node at (-2.5,1.8) (hi) {$\bm h_i$};
    \node at (2.5,1.8) (hj) {$\bm h_j$};
    \node at (-2.5,3) (zi) {$\bm z_i$};
    \node at (2.5,3) (zj) {$\bm z_j$};
    \path[->] 
        (x)  edge [>=latex] node[below,rotate=-25] {$t\sim\mathcal{T}$} (x1)
        (x)  edge [>=latex] node[below,rotate=25] {$t'\sim \mathcal{T}$} (x2)
        (x1)  edge [>=latex] node[left] {$f(\cdot)$} (hi)
        (x2)  edge [>=latex] node[right] {$f(\cdot)$} (hj)
        (hi)  edge [>=latex] node[left] {$g(\cdot)$} (zi)
        (hj)  edge [>=latex] node[right] {$g(\cdot)$} (zj);
    \path[<->]
        (zi)  edge [>=latex] node[above] {Maximize agreement} (zj);
\end{tikzpicture}
\end{document}