History of variational principles in physics involves integrals over an interval of time and (for fields) extended region of space. Moreover, in the usual formulation of classical action principles, the initial and final states of the system are fixed, e.g., In particular, the fixing of the "final" state appears to give the action principle a teleological character which has been controversial historically. This apparent teleology is eliminated in the quantum mechanical version of the action principle. History of variational principles in physics A variational principle in physics is an alternative method for determining the state or dynamics of a physical system, by identifying it as an
Letters in Mathematical Physics Letters in Mathematical Physics Letters in Mathematical Physics is a peer-reviewed scientific journal in mathematical physics published by Springer Science+Business Media. It publishes letters and longer research articles, occasionally also articles containing topical reviews. It is essentially a platform for the rapid dissemination of short contributions in the field of mathematical physics. In addition, the journal publishes contributions to modern mathematics in fields which have a potential physical application, and developments in theoretical physics which have potential mathematical impact. The editors are Volker Bach, Edward Frenkel, Maxim Kontsevich, Dirk Kreimer, Nikita Nekrasov, Massimo Porrati, and Daniel Sternheimer. The following services