\section{Nuclear Theory}\label{sec:Theory}

\subsection{Overview}

\subsection{The Canadian program}


\subsubsection{QCD under extreme conditions}


\subsubsection{The structure of QCD bound states} 


\subsubsection{Synergies between neutron matter, cold atoms and nuclear ground states}




\subsubsection{One and two-loop electroweak radiative corrections for electron-electron scattering}



\subsubsection{Understanding the fundamental properties of nucleons and of nuclei through electromagnetic and electroweak interactions}



\subsubsection{Nuclear reaction studies and structure of nuclei including continuum effects}




\subsubsection{Evolution of nuclear shell structure}


\subsubsection{Theoretical nuclear astrophysics}\label{sec:theo-astro}


\subsection{Beyond the next five years}


\paragraph{Lattice QCD and non-perturbative approaches} 

\paragraph{Perturbative QCD}

\paragraph{Effective field theory (EFT)}

\paragraph{Phenomenology and model-building}


\subsection{Summary}
It is essential to maintain a diverse program of research in theoretical nuclear and hadronic physics. 
A large portion of this theoretical work demands the features associated with HPC facilities; these aspects are discussed in section \ref{sec:hpc} of this document. In addition, much of the progress in theory research is linked to the mentoring of the next generation of theorists. A great opportunity therefore exists to further strengthen and grow this program with strategic investment into highly-qualified personnel who can accelerate the efforts of the recognized Canadian world leaders at the forefront of an exciting and fast-moving discipline that is intimately linked to Canadian experimental efforts in nuclear physics.