1,895 research outputs found
Constructions of optimal LCD codes over large finite fields
In this paper, we prove existence of optimal complementary dual codes (LCD
codes) over large finite fields. We also give methods to generate orthogonal
matrices over finite fields and then apply them to construct LCD codes.
Construction methods include random sampling in the orthogonal group, code
extension, matrix product codes and projection over a self-dual basis.Comment: This paper was presented in part at the International Conference on
Coding, Cryptography and Related Topics April 7-10, 2017, Shandong, Chin
Ab initio quantum dynamics using coupled-cluster
The curse of dimensionality (COD) limits the current state-of-the-art {\it ab
initio} propagation methods for non-relativistic quantum mechanics to
relatively few particles. For stationary structure calculations, the
coupled-cluster (CC) method overcomes the COD in the sense that the method
scales polynomially with the number of particles while still being
size-consistent and extensive. We generalize the CC method to the time domain
while allowing the single-particle functions to vary in an adaptive fashion as
well, thereby creating a highly flexible, polynomially scaling approximation to
the time-dependent Schr\"odinger equation. The method inherits size-consistency
and extensivity from the CC method. The method is dubbed orbital-adaptive
time-dependent coupled-cluster (OATDCC), and is a hierarchy of approximations
to the now standard multi-configurational time-dependent Hartree method for
fermions. A numerical experiment is also given.Comment: 5 figure
- …