A new family of methods involving complex coefficients for the numerical integration differential equations is presented and analyzed. They are constructed as linear combinations symmetric-conjugate compositions obtained from a basic time-symmetric integrator order 2n (n≥1). The integrators 2(n+k), k=1,2,…, preserve time-symmetry up to 4n+3 when applied with real vector fields. If in addition s...

We present the quantum computation of nuclear observables where operators interest are first decomposed in terms linear combination unitaries. Then we utilise Hadamard test and unitaries (LCU) based methods to compute expectation values. apply these calculate electric quadrupole moment deuteron. The results compared for Jordan-Wigner transformation Gray code encoding. discuss versatility our ap...

in this article, we characterize the involutiveness of the linear combination of the forma1a1 +a2a2 when a1, a2 are nonzero complex numbers, a1 is a quadratic or tripotent matrix,and a2 is arbitrary, under certain properties imposed on a1 and a2.