Trying out different things for finding the expectation

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Shakil Rafi 2024-02-29 23:01:06 -06:00
parent 0d8aa09dba
commit b06ee8c3de
6 changed files with 184 additions and 100 deletions

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.DS_Store vendored

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@ -1116,7 +1116,7 @@ Let $\mathfrak{p}_i$ for $i \in \{1,2,...\}$ be the set of functions defined for
\wid_{\hid \lp \lb \pwr^{q,\ve}_{n-1} \boxminus\tun_{\dep \lp \pwr_{n-1}^{q,\ve} \rp}\rb\rp} \lp \lb \pwr^{q,\ve}_{n-1} \boxminus\tun_{\dep \lp \pwr_{n-1}^{q,\ve} \rp}\rb\rp = 24+2=26
\end{align}
Finally Lemma \ref{comp_prop}, (\ref{(6.2.34)}), and Corollary \ref{cor:sameparal}, also tells us that:
Finally Lemma \ref{comp_prop}, (\ref{(6.2.34)}), a geometric series argument, and Corollary \ref{cor:sameparal}, also tells us that:
\begin{align}
&\param \lp \pwr_{n}^{q,\ve}\rp\\ &= \param \lp \prd^{q,\ve} \bullet\lb \pwr^{q,\ve}_{n-1} \boxminus\tun_{\dep \lp \pwr_{n-1}^{q,\ve} \rp}\rb \bullet \cpy_{2,1}\rp \nonumber \\
&= \param \lp \prd^{q,\ve} \bullet \lb \pwr^{q,\ve}_{n-1} \boxminus\tun_{\dep \lp \pwr_{n-1}^{q,\ve} \rp}\rb\rp \nonumber \\

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@ -534,7 +534,8 @@ Let $n, N,h\in \N$. Let $\delta,\ve \in \lp 0,\infty \rp $, $q\in \lp 2,\infty \
\end{align}
\item It is also the case that:
\begin{align}
&\left| \exp \lp \int^T_t fds\rp \mathfrak{u}_d^T\lp x\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \lp f\lp \lb \fx\rb_*\rp \frown x\rp \right|\nonumber\\ &\les 3\ve +2\ve \left| \mathfrak{u}_d^T\lp t,x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\mathfrak{u}_d^T\lp x \rp\nonumber
&\left| \exp \lp \int^T_t fds\rp \mathfrak{u}_d^T\lp x\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \lp f\lp \lb \fx\rb_*\rp \frown x\rp \right|\nonumber\\
&\les 3\ve +2\ve \left| \mathfrak{u}_d^T\lp t,x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\mathfrak{u}_d^T\lp x \rp\nonumber
\end{align}
Where, as per Lemma \ref{mathsfE}, $\mathfrak{e}$ is defined as:
\begin{align}
@ -695,12 +696,7 @@ Note that for a fixed $T \in \lp 0,\infty \rp$ it is the case that $u_d\lp t,x \
\end{center}
\end{remark}
\section{The $\mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega,\fn}$ network}
\begin{definition}[The Kahane-Kintchine Constant]
Let $p,q \in \lp 0,\infty\rp$. We will then denote by $\fK_{p,q}\in \lb 0,\infty\rb$, the extended real number given by:
\begin{align}
\fK_{p,q} = \sup \left\{ c \in \lb 0,\infty \rp : \lb \exists \text{ an }\R-\text{Banach Space} \rb \right\}
\end{align}
\end{definition}
\begin{lemma}\label{lem:sm_sum}
Let $\nu_1,\nu_2,\hdots, \nu_n \in \neu$ such that for all $i \in \{1,2,\hdots, n\}$ it is the cast that $\out\lp \nu_i\rp = 1$, and it is also the case that $\dep \lp \nu_1 \rp = \dep \lp \nu_2 \rp = \cdots =\dep \lp \nu_n\rp$. Let $x_1 \in \R^{\inn\lp \nu_1\rp},x_2 \in \R^{\inn\lp \nu_2\rp},\hdots, x_n \in \R^{\inn\lp \nu_n\rp}$ and $\fx \in \R^{\sum_{i=1}^n \inn \lp \nu_i\rp}$. It is then the case that we have that:
\begin{align}
@ -743,10 +739,21 @@ Note that for a fixed $T \in \lp 0,\infty \rp$ it is the case that $u_d\lp t,x \
\end{align}
This proves the inductive case and hence the Lemma.
\end{proof}
\begin{lemma}
Let, $\lp \Omega, \mathcal{F}, \mathbb{P}\rp$ be a probability space and let $\mathcal{X}: \Omega \rightarrow \R^d$ be a random variable with $\E\lb\mathcal{X}\rb = \mu < \infty$, and probability density function $\ff_{\cX }$. Let $g: \R^d \rightarrow \R$ be a measurable continuous function. It is then the case that
\begin{lemma}\label{var_of_rand}
Let $\lp \Omega, \cF, \mathbb{P} \rp$ be a probability space. Let $X_d: \Omega \rightarrow \R_d$ be a random variable. Let $f: \R_d \rightarrow \R$ be a function such that for all $x,\fx \in \R^d$ it is the case that $\left\| f\lp x\rp - f\lp \fx\rp\right\|_E \les \fL\left| x-\fx\right|$. It is then the case that $\var\lb f\lp X_d\rp\rb \les 2\fL^2\var\lb X_d\rb$.
\end{lemma}
\begin{proof}
Let $\fX_d$ be an i.i.d. copy of $X_d$. As such it is the case that $\cov \lp X_d, \fX_d\rp = 0$, whence it is the case that $\var\lb X_d, \fX_d\rb = \var\lb X_d\rb + \var\lb \fX_d\rb = \var[X_d] + \var\lb -\fX_d\rb = \var\lb X_d - \fX_d\rb = 2\var\lb X_d\rb$. Note that $f\lp X_d\rp$ and $f\lp \fX_d\rp$ are also indepentend and thus $\cov\lp f\lp X_d\rp,f\lp \fX_d\rp\rp = 0$, and whence we get that $\var\lb f\lp X_d\rp - f\lp \fX_d\rp\rb = 2\var \lb \fX_d\rb$. This then yields that:
\begin{align}
2\var \lb f\lp X_d\rp\rb &= \var\lb f\lp X_d\rp - f\lp \fX_d\rp\rb \nonumber\\
&= \E \lb \lp f\lp X_d\rp -f\lp \fX_d\rp\rp^2\rb - \lp \E \lb f\lp X_d\rp - f\lp \fX_d\rp\rb\rp^2 \nonumber \\
&= \E \lb \lp f\lp X_d\rp -f\lp \fX_d\rp\rp^2\rb \nonumber\\
&= \fL^2\cdot \E \lb \lp X_d - \fX_d \rp^2\rb \nonumber\\
&= \fL^2\cdot 2 \var \lb X_d\rb \nonumber\\
\implies \var \lb f\lp X_d\rp\rb &= \fL^2\cdot \var\lb X_d\rb
\end{align}
This proves the Lemma.
\end{proof}
\begin{lemma}[R\textemdash, 2024, Approximants for Brownian Motion]
Let $t \in \lp 0,\infty\rp$ and $T \in \lp t,\infty\rp$. Let $\lp \Omega, \mathcal{F}, \mathbb{P}\rp$ be a probability space. Let $n,N\in \N$, and $h \in \lp 0, \infty \rp$. Let $\delta,\ve \in \lp 0,\infty \rp $, $q\in \lp 2,\infty \rp$, satisfy that $\delta = \ve \lp 2^{q-1} +1\rp^{-1}$. Let $f:[t, T] \rightarrow \R$ be continuous almost everywhere in $\lb t, T \rb$. Let it also be the case that $f = g \circ \fh$, where $\fh: \lb t,T\rb \rightarrow \R^d$, and $g: \R^d \rightarrow \R$. Let $t=t_0 \les t_1\les \cdots \les t_{N-1} \les t_N=T$ such that for all $i \in \{0,1,...,N\}$ it is the case that $h = \frac{T-t}{N}$, and $t_i = t_0+i\cdot h$ . Let $\mathbf{t} = \lb t_0 \: t_1\: \cdots t_N \rb$ and as such let $f\lp\lb \mathbf{t} \rb_{*,*} \rp = \lb f(t_0) \: f(t_1)\: \cdots \: f(t_N) \rb$. Let $u_d \in C \lp \R^d,\R\rp$ satisfy for all $d \in \N$, $t \in \lb 0,T\rb$, $x \in \R^d$ that:
@ -795,7 +802,7 @@ Let $t \in \lp 0,\infty\rp$ and $T \in \lp t,\infty\rp$. Let $\lp \Omega, \mathc
\end{align}
\item It is also the case that:
\begin{align}
&\left| \mathbb{E} \lb \exp \lp \int^T_t f\lp \mathcal{X}^{d,t,x}_{r}\rp ds\rp u_d\lp T,\mathcal{X}^{d,t,x}_{r,\omega_i}\rp \rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega,\fn}\rp\right| \\
&\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp\rb \rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp\right| \nonumber\\
&\les 3\ve +2\ve \left| \fu^T_d\lp x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\fu^T_d\lp x \rp\nonumber
\end{align}
Where, as per Lemma \ref{mathsfE}, $\mathfrak{e}$ is defined as:
@ -831,100 +838,177 @@ Let $t \in \lp 0,\infty\rp$ and $T \in \lp t,\infty\rp$. Let $\lp \Omega, \mathc
&\les \mathfrak{n}^2\cdot \param \lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \nonumber \\
&\les \fn^2 \cdot \lb \frac{360q}{q-2} \lb \log_2 \lp \ve^{-1} \rp +q+1 \rb +324+ 48n\right. \nonumber\\ &\left. +24 \wid_{\hid\lp \mathsf{G}_d\rp}\lp \mathsf{G}_d\rp + 4\max \left\{\param \lp \mathsf{E}^{N,h,q,\ve}_{n}\rp, \param \lp \mathsf{G}_d\rp \right\} \rb
\end{align}
Now observe that by the triangle inequality, we have that:
\begin{align}
&\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right| \label{big_eqn_lhs} \\
&=\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \inst_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb\right| \nonumber\\
&\les \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\label{big_eqn_rhs_summand_1} \\
&+\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \rp \cdot \fu_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rb \rb - \real_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb\right| \label{big_eqn_lhs_summand_2}
\end{align}
Observe that by the triangle inequality, the absolute homogeneity condition for norms, the fact that the Brownian motions are independent of each other, Lemma \ref{lem:sm_sum}, the fact that $\mathfrak{n}\in \N$, the fact that the upper limit of error remains bounded by the same bound for all $\omega_i \in \Omega$, and Lemma \ref{sum_of_errors_of_stacking}, then renders the second summand, (\ref{big_eqn_lhs_summand_2}), as:
Observe that the absolute homogeneity condition for norms, the fact that the Brownian motions are independent of each other, Lemma \ref{lem:sm_sum}, the fact that $\mathfrak{n}\in \N$, the fact that the upper limit of error remains bounded by the same bound for all $\omega_i \in \Omega$, and Lemma \ref{sum_of_errors_of_stacking}, then yields us:
\begin{align}
&\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp\rb \rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp\right|\nonumber \\
&\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp\rb \rb - \real_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp\rb\right| \nonumber \\
&\les \left|\frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1} \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lp \real_{\rect}\lb \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb \right| \nonumber \\
&\les \cancel{\frac{1}{\mathfrak{n}} \sum^{\mathfrak{n}}_{i=1}}\left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i} \rp \right| \nonumber\\
&\les \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right| \nonumber
&\les \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right| \nonumber \\
&\les 3\ve +2\ve \left| \mathfrak{u}_d^T\lp t,x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\mathfrak{u}_d^T\lp x \rp\nonumber
\end{align}
This renders (\ref{big_eqn_lhs}) as:
\end{proof}
% Now observe that by the triangle inequality, we have that:
% \begin{align}
% &\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right| \label{big_eqn_lhs} \\
% &=\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \inst_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb\right| \nonumber\\
% &\les \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\label{big_eqn_rhs_summand_1} \\
% &+\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \rp \cdot \fu_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rb \rb - \real_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb\right| \label{big_eqn_lhs_summand_2}
% \end{align}
% Observe that by the triangle inequality, the absolute homogeneity condition for norms, the fact that the Brownian motions are independent of each other, Lemma \ref{lem:sm_sum}, the fact that $\mathfrak{n}\in \N$, the fact that the upper limit of error remains bounded by the same bound for all $\omega_i \in \Omega$, and Lemma \ref{sum_of_errors_of_stacking}, then renders the second summand, (\ref{big_eqn_lhs_summand_2}), as:
% \begin{align}
% &\left| \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp\rb \rb - \real_{\rect}\lb \frac{1}{\mathfrak{n}} \triangleright\lp \sm_{\mathfrak{n},1}\bullet\lb \boxminus_{i=1}^{\mathfrak{n}} \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp\rb\right| \nonumber \\
% &\les \left|\frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1} \exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lp \real_{\rect}\lb \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rb\rp \rb \right| \nonumber \\
% &\les \cancel{\frac{1}{\mathfrak{n}} \sum^{\mathfrak{n}}_{i=1}}\left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i} \rp \right| \nonumber\\
% &\les \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right| \nonumber
% \end{align}
\begin{corollary}
Let $N,n,\fn \in \N$, $h,\ve \in \lp 0,\infty\rp$, $q\in\lp 2,\infty\rp$, given $\mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d, \Omega, \fn}$, the Monte Carlo standard error for approximating $\exp \lp \int_t^T f\lp \mathcal{X}^{d,t,x}_{r,\Omega}\rp ds \cdot u_d^T\lp \mathcal{X}^{d,t,x}_{r,\Omega}\rp\rp$ is:
\begin{align}
s
\end{align}
\end{corollary}
\begin{proof}
Note that $\fu^T$ is deterministic, and $\cX^{d,t,x}_{r,\Omega}$ is a $d$-vector of random variables, where $\mu = \mymathbb{0}_d$, and $\Sigma = \mathbb{I}_d$. Whence we have that:
\begin{align}
&\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right| \nonumber \\
&\les \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right| \nonumber \\
&+\left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|
\var \lb \fu^T\lp x\rp\rb &= \lb \nabla \fu^T \lp x\rp\rb^\intercal \cdot \mathbb{I}_d \cdot \nabla \fu^T\lp x\rp + \frac{1}{2}\cdot \Trace\lp \Hess_x^2 \lp f\rp\lp x\rp\rp \nonumber \\
&= \lb \nabla \fu^T\lp x\rp \rb_*^2 + \frac{1}{2}\cdot \Trace\lp \Hess_x^2\lp f\rp\lp x\rp\rp
\end{align}
Taking the expectation on both sides of this inequality, and applying the linearity and monotonicity of expectation yields:
We will call the right hand side of the equation above as $\fU.$
For the second factor in our product consider the following:
\begin{align}
&\E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right|\rb \label{big_eqn_stage_2_lhs}\\
&\les \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\rb \label{big_eqn_stage_2_rhs_1} \\
&+\E\lb \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|\rb \label{big_eqn_stage_2_rhs_2}
\cY^{d,t}_{x,s} = \int_t^T\alpha_d \circ \cX^{d,t,x}_{r,\Omega}ds
\end{align}
Consider now, the Lyapunov inequality applied to (\ref{big_eqn_stage_2_rhs_1}), which renders it as:
Whose Reimann sum, with $\Delta t = \frac{T-t}{n}$ and $t_k = t+k\Delta t$, and Lemma \ref{var_of_rand} is thus rendered as:
\begin{align}
&\E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\rb \nonumber\\
&\les \lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|^2\rb \rp^{\frac{1}{2}} \label{where_grohs_will be applied}
\cY_n &= \Delta t \lb \sum^{n-1}_{k=0} \alpha \circ \cX^{d,t,x}_{r,\Omega}\lp t_k\rp\rb \nonumber\\
\var\lb \cY_n \rb &= \var \lb \Delta_t\sum^{n-1}_{k=0}\alpha \circ \cX^{d,t,x}_{r,\Omega}\lp t_k\rp\rb \nonumber\\
&= \lp\Delta t\rp^2 \sum^{n-1}_{k=0}\lb \var \lb \alpha \circ \cX^{d,t,x}_{r,\Omega}\lp t_k\rp \rb\rb \nonumber\\
&\les \lp \Delta t\rp^2 \sum^{n-1}_{k=0}\lb \fL^2\cdot \var\lp \cX^{d,t,x}_{r,\Omega}\lp t_k\rp\rp\rb \nonumber\\
&=\lp \fL\Delta t\rp^2 \sum^{n-1}_{k=0}\lb \var \lp \cX^{d,t,x}_{r,\Omega}\lp t_k\rp\rp \rb
\end{align}
Then, \cite[Corollary~2.6]{grohsetal} applied to (\ref{where_grohs_will be applied}), then yields that:
\textbf{Alternatively}:
\begin{align}
&\lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|^2\rb \rp^{\frac{1}{2}} \nonumber\\
&\les 2\sqrt{\frac{1}{\fn}} \lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb \right|^2\rb \rp^{\frac{1}{2}}
\end{align}
Looking back at (\ref{big_eqn_stage_2_rhs_2}), we see that the monotonicity and linearity of expectation tells us that:
\begin{align}
&\E\lb \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|\rb \\
&\les \E \lb 3\ve +2\ve \left| \fu^T_d\lp x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\fu^T_d\lp x \rp\rb \\
&\les 3\ve +2\ve \cdot\E\lb \left| \fu^T_d\lp x\rp\right|^q\rb + 2\ve \cdot \E \lb \left| \exp \lp \int^b_afdx\rp\right|^q\rb + \ve \cdot\E \lb \left| \exp \lp \int^b_a f dx\rp - \mathfrak{e}\right|^q\rb -\fe\cdot \E \lb \fu_d^T \lp x\rp\rb \nonumber\\
\end{align}
Note that:
\begin{align}
\E\lb \mathcal{X}^{d,t,x}_s\rb &= \E\lb x + \int^t_s \sqrt{2} d\mathcal{W}^d_r\rb \nonumber\\
&\les x + \sqrt{2}\cdot\E \lb \int^t_s d\mathcal{W}^d_r \rb \\
&= x + \sqrt{2}\cdot \E \lb \mathcal{W}^d_{t-s}\rb \\
&= x
\end{align}
Consider now:
\begin{align}
\va \lb \cX^{d,t,x}_s\rb &= \va \lb x + \int^t_s \sqrt{2}d\cW^d_r\rb \nonumber \\
&= \E \lb\lp x+\int^t_s\sqrt{2}d\cW^d_r - \E \lb x+\int^t_s\sqrt{2}d\cW^d_r\rb\rp^2\rb \nonumber\\
&=\E \lb\lp x+\int^t_s\sqrt{2}d\cW^d_r -x\rp^2\rb \nonumber \\
&=2\cdot \E\lb \lp \int^t_s d\cW_r^d\rp^2\rb \nonumber\\
&=2\cdot \E \lb \lp \cW^d_{t-s}\rp^2\rb
&\var \lb \int_t^T\alpha \circ \cX\rb \\
&=\E \lb \lp \int^T_t \alpha \circ \cX \rp^2\rb - \lp \E \lb \int^T_t \alpha \circ \cX \rb\rp^2 \\
&=\E \lb \int^T_t\lp \alpha \circ \cX \rp^2\rb - \lp \int_t^T \E \lb \alpha \circ \cX \rb\rp^2 \\
&=
\end{align}
Note now that:
\begin{align}
\va \lb \cW^d_{t-s}\rb &= \E \lb \lp \cW_{t-s}^d\rp^2\rb - \E \lb \cW^d_{t-s}\rb^2 \nonumber \\
\E\lb \lp \cW^d_{t-s}\rp^2\rb &= \lp t-s \rp\mathbb{I}_d \\
2\cdot \E\lb \lp \cW^d_{t-s}\rp^2\rb &= 2\lp t-s\rp\mathbb{I}_d
\end{align}
Now note that since $\cW^d_r$ are standard Brownian motions, and their expectation and variance are $\mymathbb{0}_d$ and $\mathbb{I}_d$ respectively. Whence it is the case that the probability density function for $\cW_{t-s}^d$ is:
\begin{align}
\ff_{\cW^d_{t-s}} \lp x\rp= \lp 2\pi\rp^{-\frac{d}{2}}\lp t-s\rp^{-\frac{1}{2}}\exp \lp \frac{-1}{2(t-s)}\mymathbb{e}_{1,d}\cdot \lb x \rb_*^2\rp
\end{align}
However $\cX^{d,t,x}_s$ is a shifted normal distribution, specifically shifted by $x$. Its p.d.f. is thus:
\begin{align}
\ff_{\cX^{d,t,x}_s}\lp \scrX \rp = \lp 2\pi\rp^{-\frac{d}{2}}\lp t-s\rp^{-\frac{1}{2}}\exp \lp \frac{-1}{2(t-s)}\mymathbb{e}_{1,d}\cdot \lb \scrX +x\rb_*^2\rp
\end{align}
The Law of the Unconscious Statistician then says that:
\begin{align}
\E \lb \fu^T_d \lp \cX^{d,t,x}_s\rp\rb = \int_{\R^d}\fu^T_d\lp \scrX\rp\cdot \ff_{\cX^{d,t,x}_s}\lp \scrX\rp d\scrX
\end{align}
And further that:
\begin{align}
\E \lb \alpha_d \lp \cX^{d,t,x}_s\rp\rb = \int_{\R^d} \alpha_d\lp \scrX\rp\cdot \ff_{\cX^{d,t,x}_s}\lp \scrX\rp d\scrX
\end{align}
Note that since $\alpha_d$ is Lipschitz with constant $\fL$ we may say that for $\fX^x_t = \cX_t -x$ that:
\begin{align}
\left| \alpha_d\circ \fX^x_t -\alpha_d \circ \fX^x_0 \right| &\les \fL \cdot\left|\fX^x_t - \fX^x_0\right| \nonumber\\
\implies \left| \alpha_d \circ \fX^x_t - \alpha_d\lp 0\rp\right| &\les \fL \left| \fX^x_t-0\right| \nonumber \\
\implies \alpha_d \circ \fX^x_t &\les \alpha_d\lp 0\rp + \fL t
\end{align}
Thus it is the case that:
\begin{align}
\left| \E \lb \int^T_t \alpha_d \circ \fX_s^t ds \rb\right| &\les \left| \E \lb \int^T_t \alpha_d \lp 0\rp + \fL s ds\rb\right| \nonumber\\
&\les \left| \E \lb \int^T_t\alpha_d\lp 0\rp ds +\int^T_t \fL s ds\rb\right| \nonumber\\
&\les |\alpha_d\lp 0\rp |\lp T-t\rp + \fL \lp \frac{T^2-t^2}{2} \rp
\end{align}
We will call the right hand side as $\mathfrak{E}$.
\textcolor{red}{\textbf{Need to re-examine $\fu^T_d, \alpha_d$}}
Note that It\^o's Lemma allows us to conclude that:
\begin{align}
d\:\alpha_d \lp \cX^{d,t,x}_s\rp = \alpha_d^{'}\lp \cX^{d,t,x}_s\rp d\cX_t+\alpha_d^{''}\lp \cX_t\rp dt
\end{align}
Now note this that Fubini's theorem states that:
\begin{align}\label{fubinis_to_integral}
\E \lb \int^T_t \alpha_d \circ \cX^{d,t,x}_s ds\rb = \int^T_t \E \lb \alpha_d\circ \cX^{d,t,x}_s\rb ds
\end{align}
And it is also the case that:
\begin{align}
\left| \E \lb \lp \int^T_t \alpha_d \circ \fX^x_t \rp^2\rb\right| &\les \left| \E \lb \iint_{s,\fs=t}^T \lp \alpha_d \circ \fX^x_s\rp\lp \alpha_d \circ \fX^x_\fs\rp\rb dsd\fs\right| \nonumber\\
&\les |\alpha_d\lp 0\rp|^2\lp T-t\rp^2 +2\fL |\alpha_d\lp 0\rp |\lp T-t\rp\lp \frac{T^2-t^2}{2}\rp + \fL^2\lp \frac{T^2-t^2}{2}\rp \nonumber
\end{align}
Thus it is the case that:
\begin{align}
\var\lp \int_t^T\alpha_d \circ \fX^x_t\rp &\les |\alpha_d\lp 0\rp|^2\lp T-t\rp^2 +2\fL |\alpha_d\lp 0\rp |\lp T-t\rp\lp \frac{T^2-t^2}{2}\rp + \fL^2\lp \frac{T^2-t^2}{2}\rp \nonumber\\
&+ |\alpha_d\lp 0\rp |\lp T-t\rp + \fL \lp \frac{T^2-t^2}{2} \rp \nonumber
\end{align}
Denote the right hand side of the equation above as $\fV$. The the variance vecomes:
\end{proof}
\end{proof}
\begin{corollary}
We may see that
\end{corollary}
% This renders (\ref{big_eqn_lhs}) as:
% \begin{align}
% &\left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right| \nonumber \\
% &\les \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right| \nonumber \\
% &+\left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|
% \end{align}
% Taking the expectation on both sides of this inequality, and applying the linearity and monotonicity of expectation yields:
% \begin{align}
% &\E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp\rb - \real_{\rect}\lp \mathsf{UES}^{N,h,q,\ve}_{n,\mathsf{G}_d,\Omega, \fn}\rp \right|\rb \label{big_eqn_stage_2_lhs}\\
% &\les \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\rb \label{big_eqn_stage_2_rhs_1} \\
% &+\E\lb \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|\rb \label{big_eqn_stage_2_rhs_2}
% \end{align}
% Consider now, the Lyapunov inequality applied to (\ref{big_eqn_stage_2_rhs_1}), which renders it as:
% \begin{align}
% &\E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|\rb \nonumber\\
% &\les \lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|^2\rb \rp^{\frac{1}{2}} \label{where_grohs_will be applied}
% \end{align}
% Then, \cite[Corollary~2.6]{grohsetal} applied to (\ref{where_grohs_will be applied}), then yields that:
% \begin{align}
% &\lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb - \frac{1}{\mathfrak{n}}\lb \sum^{\mathfrak{n}}_{i=1}\lb \exp \lp \int_t^T f ds \rp \cdot \fu_d^T\lp x\rp\rb \rb \right|^2\rb \rp^{\frac{1}{2}} \nonumber\\
% &\les 2\sqrt{\frac{1}{\fn}} \lp \E \lb \left| \E \lb \exp \lp \int^T_t f ds\rp \fu_d^T\lp x\rp \rb \right|^2\rb \rp^{\frac{1}{2}}
% \end{align}
% Looking back at (\ref{big_eqn_stage_2_rhs_2}), we see that the monotonicity and linearity of expectation tells us that:
% \begin{align}
% &\E\lb \left| \exp \lp \int^T_tf\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp ds \cdot u^T_d\lp \mathcal{X}^{d,t,x}_{r,\omega_i}\rp\rp - \real_{\rect}\lp \mathsf{UEX}^{N,h,q,\ve}_{n,\mathsf{G}_d,\omega_i}\rp \right|\rb \\
% &\les \E \lb 3\ve +2\ve \left| \fu^T_d\lp x\rp\right|^q+2\ve \left| \exp \lp \int^b_afdx\rp\right|^q + \ve \left| \exp \lp \int^b_afdx\rp - \mathfrak{e}\right|^q -\mathfrak{e}\fu^T_d\lp x \rp\rb \\
% &\les 3\ve +2\ve \cdot\E\lb \left| \fu^T_d\lp x\rp\right|^q\rb + 2\ve \cdot \E \lb \left| \exp \lp \int^b_afdx\rp\right|^q\rb + \ve \cdot\E \lb \left| \exp \lp \int^b_a f dx\rp - \mathfrak{e}\right|^q\rb -\fe\cdot \E \lb \fu_d^T \lp x\rp\rb \nonumber\\
% \end{align}
% Note that:
% \begin{align}
% \E\lb \mathcal{X}^{d,t,x}_s\rb &= \E\lb x + \int^t_s \sqrt{2} d\mathcal{W}^d_r\rb \nonumber\\
% &\les x + \sqrt{2}\cdot\E \lb \int^t_s d\mathcal{W}^d_r \rb \\
% &= x + \sqrt{2}\cdot \E \lb \mathcal{W}^d_{t-s}\rb \\
% &= x
% \end{align}
% Consider now:
% \begin{align}
% \va \lb \cX^{d,t,x}_s\rb &= \va \lb x + \int^t_s \sqrt{2}d\cW^d_r\rb \nonumber \\
% &= \E \lb\lp x+\int^t_s\sqrt{2}d\cW^d_r - \E \lb x+\int^t_s\sqrt{2}d\cW^d_r\rb\rp^2\rb \nonumber\\
% &=\E \lb\lp x+\int^t_s\sqrt{2}d\cW^d_r -x\rp^2\rb \nonumber \\
% &=2\cdot \E\lb \lp \int^t_s d\cW_r^d\rp^2\rb \nonumber\\
% &=2\cdot \E \lb \lp \cW^d_{t-s}\rp^2\rb
% \end{align}
%
%Note now that:
%\begin{align}
% \va \lb \cW^d_{t-s}\rb &= \E \lb \lp \cW_{t-s}^d\rp^2\rb - \E \lb \cW^d_{t-s}\rb^2 \nonumber \\
% \E\lb \lp \cW^d_{t-s}\rp^2\rb &= \lp t-s \rp\mathbb{I}_d \\
% 2\cdot \E\lb \lp \cW^d_{t-s}\rp^2\rb &= 2\lp t-s\rp\mathbb{I}_d
%\end{align}
%Now note that since $\cW^d_r$ are standard Brownian motions, and their expectation and variance are $\mymathbb{0}_d$ and $\mathbb{I}_d$ respectively. Whence it is the case that the probability density function for $\cW_{t-s}^d$ is:
%\begin{align}
% \ff_{\cW^d_{t-s}} \lp x\rp= \lp 2\pi\rp^{-\frac{d}{2}}\lp t-s\rp^{-\frac{1}{2}}\exp \lp \frac{-1}{2(t-s)}\mymathbb{e}_{1,d}\cdot \lb x \rb_*^2\rp
%\end{align}
%However $\cX^{d,t,x}_s$ is a shifted normal distribution, specifically shifted by $x$. Its p.d.f. is thus:
%\begin{align}
% \ff_{\cX^{d,t,x}_s}\lp \scrX \rp = \lp 2\pi\rp^{-\frac{d}{2}}\lp t-s\rp^{-\frac{1}{2}}\exp \lp \frac{-1}{2(t-s)}\mymathbb{e}_{1,d}\cdot \lb \scrX +x\rb_*^2\rp
%\end{align}
%The Law of the Unconscious Statistician then says that:
%\begin{align}
% \E \lb \fu^T_d \lp \cX^{d,t,x}_s\rp\rb = \int_{\R^d}\fu^T_d\lp \scrX\rp\cdot \ff_{\cX^{d,t,x}_s}\lp \scrX\rp d\scrX
%\end{align}
%And further that:
%\begin{align}
% \E \lb \alpha_d \lp \cX^{d,t,x}_s\rp\rb = \int_{\R^d} \alpha_d\lp \scrX\rp\cdot \ff_{\cX^{d,t,x}_s}\lp \scrX\rp d\scrX
%\end{align}
%
%\textcolor{red}{\textbf{Need to re-examine $\fu^T_d, \alpha_d$}}
%Note that It\^o's Lemma allows us to conclude that:
%\begin{align}
% d\:\alpha_d \lp \cX^{d,t,x}_s\rp = \alpha_d^{'}\lp \cX^{d,t,x}_s\rp d\cX_t+\alpha_d^{''}\lp \cX_t\rp dt
%\end{align}
%
%Now note this that Fubini's theorem states that:
%\begin{align}\label{fubinis_to_integral}
% \E \lb \int^T_t \alpha_d \circ \cX^{d,t,x}_s ds\rb = \int^T_t \E \lb \alpha_d\circ \cX^{d,t,x}_s\rb ds
%\end{align}
%
%
%\end{proof}

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\DeclareMathOperator{\supp}{supp}
\DeclareMathOperator{\domain}{Domain}
\DeclareMathOperator{\lip}{Lip}
\DeclareMathOperator{\var}{Var}
\DeclareMathOperator{\var}{\mathbb{V}}
\DeclareMathOperator{\cov}{Cov}
\DeclareMathOperator{\unif}{Unif}
\DeclareMathOperator{\dropout}{Dropout}

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