diff --git a/g.tex b/g.tex index 5bd1dce..4ab7180 100644 --- a/g.tex +++ b/g.tex @@ -418,43 +418,42 @@ We shall not here insist on these practical details that are discussed, for exam During the simulation, walkers move from state to state with the possibility of being trapped a certain number of times on the same state before exiting to a different state. This fact can be exploited in order to integrate out some part of the dynamics, thus leading to a reduction of the statistical -fluctuations. This idea was proposed some time ago \cite{Assaraf_1999A,Assaraf_1999B,Caffarel_2000} and applied to the SU(N) one-dimensional Hubbard model. +fluctuations. This idea was proposed some time ago \cite{Assaraf_1999A,Assaraf_1999B,Caffarel_2000} and applied to the SU($N$) one-dimensional Hubbard model. -Let us consider a given state $|i\rangle$. The probability that the walker remains exactly $n$ times on $|i\rangle$ ($n$ from -1 to $\infty$) and then exits to a different state $j$ is +Considering a given state $\ket{i}$, the probability that a walker remains exactly $n$ times in $\ket{i}$ (with $1 \le n < \infty$) and then exits to a different state $j$ (with $j \neq i$) is \be - \cP_{i \to j}(n) = \qty(p_{i \to i})^{n-1} p_{i \to j} \qq{$j \ne i$.} + \cP_{i \to j}(n) = \qty(p_{i \to i})^{n-1} p_{i \to j}. \ee Using the relation \be \sum_{n=1}^{\infty} (p_{i \to i})^{n-1}=\frac{1}{1-p_{i \to i}} \ee -and the normalization of the $p_{i \to j}$, Eq.~\eqref{eq:sumup}, we verify that the probability is normalized to one +and the normalization of the $p_{i \to j}$'s [see Eq.~\eqref{eq:sumup}], one can check that the probability is properly normalized, \ie, \be \sum_{j \ne i} \sum_{n=1}^{\infty} \cP_{i \to j}(n) = 1. \ee -The probability of being trapped during $n$ steps is obtained by summing over all possible exit states +Naturally, the probability of being trapped during $n$ steps is obtained by summing over all possible exit states \be -P_i(n)=\sum_{j \ne i} \cP_{i \to j}(n) = \qty(p_{i \to i})^{n-1} \qty( 1 - p_{i \to i} ). +P_i(n)=\sum_{j \ne i} \cP_{i \to j}(n) = \qty(p_{i \to i})^{n-1} \qty( 1 - p_{i \to i} ), \ee -This probability defines a Poisson law with an average number $\bar{n}_i$ of trapping events given by +and this defines a Poisson law with an average number of trapping events \be \bar{n}_i= \sum_{n=1}^{\infty} n P_i(n) = \frac{1}{1 -p_{i \to i}}. \ee -Introducing the continuous time $t_i=n_i\tau$ the average trapping time is given by +Introducing the continuous time $t_i = n \tau$, the average trapping time is thus given by \be \bar{t_i}= \frac{1}{H^+_{ii}-(\EL^+)_{i}}. \ee -Taking the limit $\tau \to 0$, the Poisson probability takes the usual form +In the limit $\tau \to 0$, the Poisson probability takes the usual form \be - P_{i}(t) = \frac{1}{\bar{t}_i} \exp(-\frac{t}{\bar{t}_i}) + P_{i}(t) = \frac{1}{\bar{t}_i} \exp(-\frac{t}{\bar{t}_i}). \ee -The time-averaged contribution of the \titou{on-state} weight can be easily calculated to be +The time-averaged contribution of the on-state weight can be easily calculated to be \be \bar{w}_i= \sum_{n=1}^{\infty} w^n_{ii} P_i(n)= \frac{T_{ii}}{T^+_{ii}} \frac{1-T^+_{ii}}{1-T_{ii}} \ee -Details of the implementation of the effective dynamics can be in found in Refs.~\onlinecite{Assaraf_1999B} and \onlinecite{Caffarel_2000}. +Details of the implementation of this effective dynamics can be in found in Refs.~\onlinecite{Assaraf_1999B} and \onlinecite{Caffarel_2000}. %=======================================% \subsection{General domains}