  The abundance of infrared singularities in gauge theories due to unresolved
emission of massless particles (soft and collinear) represents the main
difficulty in perturbative calculations. They are typically regularized in
dimensional regularization, and their subtraction is usually achieved
independently for virtual and real corrections. In this paper, we introduce a
new method based on the loop-tree duality (LTD) theorem to accomplish the
summation over degenerate infrared states directly at the integrand level such
that the cancellation of the infrared divergences is achieved simultaneously,
and apply it to reference examples as a proof of concept. Ultraviolet
divergences, which are the consequence of the point-like nature of the theory,
are also reinterpreted physically in this framework. The proposed method opens
the intriguing possibility of carrying out purely four-dimensional
implementations of higher-order perturbative calculations at next-to-leading
order (NLO) and beyond free of soft and final-state collinear subtractions.
