### Level 1. Qualitative understanding.

Magnetic domains are areas with homogeneously distributed magnetization vector inside. The domains existence was proved by many experiments. But what is the reason for domain appearance in a sample? Domains appear to minimize the total system energy....

### Level 2. A simplified theory of stripe domain structure.

Now we know that magnetic domains appear to minimize the total system energy. Indeed, as usually any system try to reach the state in which its total energy becomes minimal one. The domain appearence minimizes the total energy of the sample by a lowering...

### Level 3. Rigorous theory of stripe DS with negligible narrow walls.

Now we analyze magnetization process in a film with the stripe domain structure (DS ) neglecting the domain wall width, see Fig.2. The total volume energy density of DS is the sum of the domain wall, Zeeman and demagnetizing energies:
(1.8)...