Sharif Digital Repository

In this study, the effect of rigid rotation on the dynamical and thermodynamic properties of Dirac fermions in a chiral environment is investigated. Using the framework of quantum field theory, the Dirac equation is solved in the presence of rigid rotation, and the corresponding propagator is derived using the Fock-Schwinger method. The results demonstrate that the angular velocity Ω acts as an effective chemical potential and plays a significant role in the dynamical behavior of fermions. Using the fermion propagator arising in the first part of this work, the chiral current phenomena, including the Chiral Vortical and the Chiral Vortical Separation Effect is also examined in the presence... 

In this thesis, we want to discuss about some aspects of semantics and proof theory of U logic. This logic was introduced by Ardehsir and Vaezian in 2012. U Logic was introduced with intention of unifying Sambin Basic Logic(Sambin in 1997) and Visser Basic Logic(Visser in 1981). These two basic logics are two of the most significant basic logics that were introduced. This thesis begins with addressing U logic proof system. Subsequently, we introduce three algebraic semantics for this logic. The first one was introduced by Girard for Linear logic. The second one was introduced by Sambin for Sambin Basic Logic. Then we introduce the third one specially for U logic. In fact, we have proof... 

In the region of intermediate densities of quark matter, the possibility of formation of inhomogeneous phases, such as dual chiral density wave phase exists. These kinds media can be formed in the heavy-ion collisions and in the core of dense stars. Since these media are rotating and magnetic, in this thesis we investigated the effects of a finite chemical potential, a rigid rotation and a constant magnetic field on the energy spectrum of dual chiral density wave in the context of Nambu-Jona-Lasino model. In the presence of magnetic fields, the energy spectrum of this system become asymmetric, and hence it gives rise to additional charge in the vacuum of the model. We have found that the... 

One of the most essential concepts for describing neutron stars is investigating their radial mass distribution or mass-radius relation. The aim of this thesis is to evaluate radial mass distribution of neutron stars in the presence of magnetic fields. To achieve this objective we use the Tolman- Oppenheimer-Volkoff equation of hydrostatic equilibrium for non-rotating cases and the Hartle- Thorne equations for rotating cases. olving these equations depends on determination of equation of state of neutron star in the presence of magnetic fields. For determining the corresponding equation of state, one can use QCD-like non-perturbative models, in particular Nambu-Jona- Lasinio (NJL) model. In...