  We develop the physics of dual kappa Poincare algebra, which we will call
dual DSR. First, we show that the dual kappa Poincare algebra is isomorphic to
de Sitter algebra and its spactime is essentially de Sitter spacetime. Second,
we show how to derive the coproduct rules for Beltrami and conformal
coordinates of de Sitter spacetime. It follows from the current literature on
de Sitter relativity that the speed of light c and the de Sitter length are the
two invariant scales of the physics of dual kappa Poincare algebra. Third, we
derive the Casimir invariant of the dual kappa Popincare algebra and use this
to derive an expression for the speed of light, our fourth result. Fifth, the
field equation for the scalar field is derived from the Casimir invariant. The
results for the coordinate speed of light and the scalar field theory are the
same as in de Sitter theory in the planar coordinate basis. Thus, we have shown
that the physics of dual kappa Poincare algebra (in the dual bicrossproduct
basis), which can be apprpriately called dual DSR, is essentially de Sitter
relativity. Sixth, we argue the existence of an observer-independent minimum
momentum. Seventh, we argue heuristically that the existence of minimum
momentum will lead to a dual generalized uncertainty principle. Finally, we
note that dual DSR is not a quantum theory of spacetime but a quantum theory of
momenta.
