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authorJaron Kent-Dobias <jaron@kent-dobias.com>2017-08-02 22:47:40 -0400
committerJaron Kent-Dobias <jaron@kent-dobias.com>2017-08-02 22:47:40 -0400
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many changes to incorporate new low-order info, small corrections to scaling functions
Diffstat (limited to 'essential-ising.tex')
-rw-r--r--essential-ising.tex34
1 files changed, 18 insertions, 16 deletions
diff --git a/essential-ising.tex b/essential-ising.tex
index ea8e9eb..c98e938 100644
--- a/essential-ising.tex
+++ b/essential-ising.tex
@@ -202,7 +202,7 @@ same singular behavior as the real part of the equilibrium free energy, and
that for small $t$, $h$, $\im F(t,h)=|t|^{2-\alpha}\fiF(h|t|^{-\beta\delta})$,
where
\[
- \fiF(X)=-A\Theta(-X)(-BX)^be^{-1/(-BX)^{\dim-1}}
+ \fiF(X)=A\Theta(-X)(-BX)^be^{-1/(-BX)^{\dim-1}}
\label{eq:im.scaling}
\]
and $\Theta$ is the Heaviside function. Results from combining an analysis of
@@ -224,14 +224,14 @@ given our scaling ansatz, yielding
\def\eqthreedeeone{
\fF^\threedee(Y/B)&=
\frac{A}{12}\frac{e^{-1/Y^2}}{Y^2}
- \bigg[4Y\Gamma(\tfrac23)E_{5/3}(-Y^{-2})
+ \bigg[\Gamma(\tfrac16)E_{7/6}(-Y^{-2})
}
\def\eqthreedeetwo{
- -\Gamma(\tfrac16)E_{7/6}(-Y^{-2})\bigg]
+ -4Y\Gamma(\tfrac23)E_{5/3}(-Y^{-2})\bigg]
}
\def\eqfourdeeone{
\fF^\fourdee(Y/B)&=
- \frac{A}{9\pi}\frac{e^{1/Y^3}}{Y^2}
+ -\frac{A}{9\pi}\frac{e^{1/Y^3}}{Y^2}
\Big[3\ei(-Y^{-3})
}
\def\eqfourdeetwo{
@@ -242,7 +242,7 @@ given our scaling ansatz, yielding
\begin{align}
&\begin{aligned}
\eqthreedeeone\\
- &\hspace{8em}
+ &\hspace{7em}
\eqthreedeetwo
\end{aligned}
\\
@@ -264,13 +264,13 @@ At the level of truncation of \eqref{eq:im.scaling} at which we are working
the Kramers--Kronig relation does not converge in \twodee. However, higher
moments can still be extracted, e.g., the susceptibility, by taking
\[
- \chi=\pd[2]Fh
- =\frac2\pi\int_{-\infty}^\infty\frac{\im F(t,h')}{(h'-h)^3}\,\dd h'.
+ \chi=\pd MH=-\frac1{T_\c}\pd[2]Fh
+ =-\frac2{\pi T_\c}\int_{-\infty}^\infty\frac{\im F(t,h')}{(h'-h)^3}\,\dd h'.
\]
With a scaling form defined by $\chi=|t|^{-\gamma}\fX(h|t|^{-\beta\delta})$,
this yields
\[
- \fX^\twodee(Y/B)=\frac{AB^2}{\pi Y^3}\big[Y(Y-1)-e^{1/Y}\ei(-1/Y)\big]
+ \fX^\twodee(Y/B)=\frac{AB^2}{\pi T_\c Y^3}\big[Y(Y-1)-e^{1/Y}\ei(-1/Y)\big]
\label{eq:sus_scaling}
\]
Scaling forms for the free energy can then be extracted by direct integration
@@ -278,9 +278,9 @@ and their constants of integration fixed by known zero field values, yielding
\begin{align}
\label{eq:mag_scaling}
\fM^\twodee(Y/B)
- &=\fM(0)+\frac{ABT_\c}{\pi}\bigg(1-\frac{Y-1}Ye^{1/Y}\ei(-1/Y)\bigg)\\
+ &=\fM(0)+\frac{AB}{\pi}\bigg(1-\frac{Y-1}Ye^{1/Y}\ei(-1/Y)\bigg)\\
\fF^\twodee(Y/B)
- &=\fF(0)+T_\c Y\bigg(\frac{\fM(0)}B+\frac{AT_\c}\pi e^{1/Y}\ei(-1/Y)\bigg)
+ &=-Y\bigg(\frac{\fM(0)}B-\frac{A}\pi e^{1/Y}\ei(-1/Y)\bigg)
\end{align}
with $F(t,h)=|t|^{2-\alpha}\fF(h|t|^{-\beta\delta})+t^{2-\alpha}\log|t|$ in
two dimensions.
@@ -325,8 +325,8 @@ $C_0^-=0.025\,536\,971\,9$ \cite{barouch.1973.susceptibility}, so that
$B=T_\c^2\fM(0)/\pi\fS(0)^2=(2^{27/16}\pi(\arcsinh1)^{15/8})^{-1}$. If we
assume incorrectly that \eqref{eq:sus_scaling} is the true asymptotic form of
the susceptibility scaling function, then
-$\chi(t,0)|t|^\gamma=\lim_{X\to0}\fX^\twodee(X)=2AB^2/\pi$ and the constant
-$A$ is fixed to $A=\pi\fX(0)/2B^2=2^{11/8}\pi^3(\arcsinh1)^{19/4}C_0^-$. The
+$\chi(t,0)|t|^\gamma=\lim_{X\to0}\fX^\twodee(X)=2AB^2/\pi T_\c$ and the constant
+$A$ is fixed to $A=\pi T_\c\fX(0)/2B^2=2^{19/8}\pi^3(\arcsinh1)^{15/4}C_0^-$. The
resulting scaling functions $\fX$ and $\fM$ are plotted as solid lines in
Fig.~\ref{fig:scaling_fits}. As can be seen, there is very good agreement
between our proposed functional forms and what is measured. However, there
@@ -349,8 +349,10 @@ where $F_n'(Y)=f_n(Y)$ and
The functions $f_n$ have been chosen to be pure integer power laws for small
argument, but vanish appropriately at large argument. This is necessary
because the susceptibility vanishes with $h|t|^{-\beta\delta}$ while bare
-polynomial corrections would not. We fit these functions to our numeric data
-for $N=0$ while requiring that $C_0^-/T_\c=\fX'(0)=c_0+2AB^2/\pi$. The
+polynomial corrections would not. We fit these functions to known moments of
+the free energy's scaling function
+\cite{mangazeev.2008.variational,mangazeev.2010.scaling} our numeric data
+for $N=0$. The
resulting curves are also plotted as dashed lines in
Fig.~\ref{fig:scaling_fits}. Our singular scaling function with one low-order
correction appears to match data quite well.
@@ -385,10 +387,10 @@ into the scaling function gives good convergence to the simulations in \twodee.
Our results should allow improved high-precision functional forms for the free
energy~\cite{caselle.2001.critical}, and should have implications for the scaling
-of correlation functions~\cite{YJXXX,XXX}. Our methods might be generalized
+of correlation functions~\cite{chen.2013.universal,wu.1976.spin}. Our methods might be generalized
to predict similar singularities in systems where nucleation and metastability
are proximate to continuous phase transitions, such as 2D superfluid
-transitions~\cite{ALHN}, the melting of 2D crystals~\cite{XXX}, and
+transitions~\cite{ambegaokar.1978.dissipation,ambegaokar.1980.dynamics}, the melting of 2D crystals~\cite{XXX}, and
freezing transitions in glasses, spin glasses, and other disordered systems.