4 files changed, 44 insertions, 0 deletions
diff --git a/content/know/category/index.md b/content/know/category/index.md
index b8f0456..ba4936c 100644
--- a/content/know/category/index.md
+++ b/content/know/category/index.md
@@ -9,5 +9,11 @@ Alphabetical list of categories in this knowledge base.
 Note that these categories might overlap,
 i.e. share certain concepts.
 
+## M
+* [Mathematics](/know/category/mathematics/)
+
+## P
+* [Physics](/know/category/physics/)
+
 ## Q
 * [Quantum mechanics](/know/category/quantum-mechanics/)
diff --git a/content/know/category/mathematics.md b/content/know/category/mathematics.md
new file mode 100644
index 0000000..e873d90
--- /dev/null
+++ b/content/know/category/mathematics.md
@@ -0,0 +1,10 @@
++++
+title = "Category: mathematics"
++++
+
+#
+
+Alphabetical list of concepts in this category.
+
+## D
+* [Dirac delta function](/know/concept/dirac-delta-function/)
diff --git a/content/know/category/physics.md b/content/know/category/physics.md
new file mode 100644
index 0000000..8bcba4d
--- /dev/null
+++ b/content/know/category/physics.md
@@ -0,0 +1,27 @@
++++
+title = "Category: physics"
++++
+
+#
+
+Alphabetical list of concepts in this category.
+
+## B
+* [Bloch's theorem](/know/concept/blochs-theorem/)
+
+## D
+* [Dirac delta function](/know/concept/dirac-delta-function/)
+* [Dirac notation](/know/concept/dirac-notation/)
+
+## P
+* [Pauli exclusion principle](/know/concept/pauli-exclusion-principle/)
+* [Probability current](/know/concept/probability-current/)
+
+## S
+* [Slater determinant](/know/concept/slater-determinant/)
+
+## T
+* [Time-independent perturbation theory](/know/concept/time-independent-perturbation-theory/)
+
+## W
+* [Wentzel-Kramers-Brillouin approximation](/know/concept/wentzel-kramers-brillouin-approximation/)
diff --git a/content/know/concept/index.md b/content/know/concept/index.md
index 7d9c183..697c622 100644
--- a/content/know/concept/index.md
+++ b/content/know/concept/index.md
@@ -10,6 +10,7 @@ Alphabetical list of concepts in this knowledge base.
 * [Bloch's theorem](/know/concept/blochs-theorem/)
 
 ## D
+* [Dirac delta function](/know/concept/dirac-delta-function/)
 * [Dirac notation](/know/concept/dirac-notation/)
 
 ## P