阐述

Lack of space disallows further treatment of the topic here.

Now we need to give a realistic and in-depth explanation from a theoretical perspective.

give a detailed explanation (about sth)

briefly explain

state in detail; adequately expound

expound a subject

set forth/elaborate on/state the facts

expound one's stand; set forth one's position

set out/set forth/explain one's reasons

set forth/explicate/expound/formulate a theory; elaborate on a theory

set forth a plan

expound the laws

set forth/expound/enunciate one's views