Approximation processes by multidimensional Bernstein-type exponential polynomials on the hypercube

In this paper we introduce a new family of Bernstein-type exponential polynomials on the hypercube $[0,1{]}^d$ and study their approximation properties. Such operators fix a multidimensional version of the exponential function and its square. In particular, we prove uniform convergence, by means of two different approaches, as well as a quantitative estimate of the order of approximation in terms of the modulus of continuity of the approximated function.