Migrate from 'jekyll-katex' to 'kramdown-math-sskatex'

1 files changed, 11 insertions, 11 deletions

diff --git a/source/know/concept/propagator/index.md b/source/know/concept/propagator/index.md
index 437c57e..54e9eb6 100644
--- a/source/know/concept/propagator/index.md
+++ b/source/know/concept/propagator/index.md
@@ -8,9 +8,9 @@ categories:
 layout: "concept"
 ---
 
-In quantum mechanics, the **propagator** $K(x_f, t_f; x_i, t_i)$
+In quantum mechanics, the **propagator** $$K(x_f, t_f; x_i, t_i)$$
 gives the probability amplitude that a particle
-starting at $x_i$ at $t_i$ ends up at position $x_f$ at $t_f$.
+starting at $$x_i$$ at $$t_i$$ ends up at position $$x_f$$ at $$t_f$$.
 It is defined as follows:
 
 $$\begin{aligned}
@@ -20,24 +20,24 @@ $$\begin{aligned}
     }
 \end{aligned}$$
 
-Where $\hat{U} \equiv \exp(- i t \hat{H} / \hbar)$ is the time-evolution operator.
+Where $$\hat{U} \equiv \exp(- i t \hat{H} / \hbar)$$ is the time-evolution operator.
 The probability that a particle travels
-from $(x_i, t_i)$ to $(x_f, t_f)$ is then given by:
+from $$(x_i, t_i)$$ to $$(x_f, t_f)$$ is then given by:
 
 $$\begin{aligned}
     P
     &= \big| K(x_f, t_f; x_i, t_i) \big|^2
 \end{aligned}$$
 
-Given a general (i.e. non-collapsed) initial state $\psi_i(x) \equiv \psi(x, t_i)$,
-we must integrate over $x_i$:
+Given a general (i.e. non-collapsed) initial state $$\psi_i(x) \equiv \psi(x, t_i)$$,
+we must integrate over $$x_i$$:
 
 $$\begin{aligned}
     P
     &= \bigg| \int_{-\infty}^\infty K(x_f, t_f; x_i, t_i) \: \psi_i(x_i) \dd{x_i} \bigg|^2
 \end{aligned}$$
 
-And if the final state $\psi_f(x) \equiv \psi(x, t_f)$
+And if the final state $$\psi_f(x) \equiv \psi(x, t_f)$$
 is not a basis vector either, then we integrate twice:
 
 $$\begin{aligned}
@@ -45,7 +45,7 @@ $$\begin{aligned}
     &= \bigg| \iint_{-\infty}^\infty \psi_f^*(x_f) \: K(x_f, t_f; x_i, t_i) \: \psi_i(x_i) \dd{x_i} \dd{x_f} \bigg|^2
 \end{aligned}$$
 
-Given a $\psi_i(x)$, the propagator can also be used
+Given a $$\psi_i(x)$$, the propagator can also be used
 to find the full final wave function:
 
 $$\begin{aligned}
@@ -56,9 +56,9 @@ $$\begin{aligned}
 \end{aligned}$$
 
 Sometimes the name "propagator" is also used to refer to
-the [fundamental solution](/know/concept/fundamental-solution/) $G$
+the [fundamental solution](/know/concept/fundamental-solution/) $$G$$
 of the time-dependent Schrödinger equation,
-which is related to $K$ by:
+which is related to $$K$$ by:
 
 $$\begin{aligned}
     \boxed{
@@ -67,4 +67,4 @@ $$\begin{aligned}
     }
 \end{aligned}$$
 
-Where $\Theta(t)$ is the [Heaviside step function](/know/concept/heaviside-step-function/).
+Where $$\Theta(t)$$ is the [Heaviside step function](/know/concept/heaviside-step-function/).