Extended Equations for Particles: Spin, General Theory and Exact Solution presents a unified theoretical framework for understanding relativistic wave equations describing particles with spins S = 0, 1/2, 1 and additional internal electromagnetic structure. Through mathematical analysis and physical interpretation, the book bridges fundamental concepts across quantum field theory, relativistic quantum mechanics, and electromagnetic theory. The text introduces methodologies for developing new relativistic systems of equations that describe particles with electromagnetic characteristics beyond electric charge. Readers will find detailed examinations of the Dirac-Kähler particle and Stueckelberg particle in various external field configurations, including Coulomb, uniform magnetic, and electric fields. Designed as both a reference for researchers and a pedagogical resource for advanced undergraduate and graduate students, this book provides a mathematically rigorous yet accessible treatment of complex theoretical physics concepts. The unified methodological approach presented throughout makes this a useful contribution to the field of relativistic quantum theory. Key Features: Develops an innovative approach that connects quantum field theory, relativistic quantum mechanics, and electromagnetic theory. Makes complex interdisciplinary concepts accessible while maintaining the mathematical rigor essential for advanced research.

Serves as a cutting-edge reference for active researchers and an accessible pedagogical resource for advanced students.