ﻻ يوجد ملخص باللغة العربية
The mean-field pictures based on the standard time-dependent variational approach have widely been used in the study of nonlinear many-boson systems such as the Bose-Hubbard model. The mean-field schemes relevant to Gutzwiller-like trial states $|F>$, number-preserving states $|xi >$ and Glauber-like trial states $|Z>$ are compared to evidence the specific properties of such schemes. After deriving the Hamiltonian picture relevant to $|Z>$ from that based on $|F>$, the latter is shown to exhibit a Poisson algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the $|Z>$-based picture. Then states $|Z>$ are shown to be a superposition of $cal N$-boson states $|xi>$ and the similarities/differences of the $|Z>$-based and $|xi>$-based pictures are discussed. Finally, after proving that the simple, symmetric state $|xi>$ indeed corresponds to a SU(M) coherent state, a dual version of states $|Z>$ and $|xi>$ in terms of momentum-mode operators is discussed together with some applications.
Building on earlier work, we discuss a general framework for exploring the cosmological dynamics of Higher Order Theories of Gravity. We show that once the theory of gravity has been specified, the cosmological equations can be written as a first-ord
We study several formulations of zero-mass relativistic equations, stressing similarities between different frameworks. It is shown that all these massless wave equations have fermionic as well as bosonic solutions.
We present a unified framework for renormalization group methods, including Wilsons numerical renormalization group (NRG) and Whites density-matrix renormalization group (DMRG), within the language of matrix product states. This allows improvements o
The analysis of the LHCb data on $X(6900)$ found in the di-$jpsi$ system is performed using a momentum-dependent Flatt{e}-like parameterization. The use of the pole counting rule and spectral density function sum rule give consistent conclusions that
We discuss a generalization of the conditions of validity of the interpolation method for the density of quenched free energy of mean field spin glasses. The condition is written just in terms of the $L^2$ metric structure of the Gaussian random vari