Initial commit

Base modular structure (phase space, Fermi function)
Initial .gitignore

beta_spectrum/base.py

@@ -0,0 +1,20 @@
+# base.py
+from __future__ import annotations
+from abc import ABC, abstractmethod
+import numpy as np
+
+
+ArrayLike = np.ndarray
+
+
+class SpectrumComponent(ABC):
+    """
+    Base class for multiplicative components of beta-spectrum
+    """
+
+    @abstractmethod
+    def __call__(self, W: ArrayLike) -> ArrayLike:
+        """
+        Evaluate component  at total energy W (in m_e units)
+        """
+        pass