13,857 research outputs found
Constraining strangeness in dense matter with GW170817
Particles with strangeness content are predicted to populate dense matter,
modifying the equation of state of matter inside neutron stars as well as their
structure and evolution. In this work, we show how the modeling of strangeness
content in dense matter affects the properties of isolated neutrons stars and
the tidal deformation in binary systems. For describing nucleonic and hyperonic
stars we use the many-body forces model (MBF) at zero temperature, including
the mesons for the description of repulsive hyperon-hyperon
interactions. Hybrid stars are modeled using the MIT Bag Model with vector
interaction (vMIT) in both Gibbs and Maxwell constructions, for different
values of bag constant and vector interaction couplings. A parametrization with
a Maxwell construction, which gives rise to third family of compact stars (twin
stars), is also investigated. We calculate the tidal contribution that adds to
the post-Newtonian point-particle corrections, the associated love number for
sequences of stars of different composition (nucleonic, hyperonic, hybrid and
twin stars), and determine signatures of the phase transition on the
gravitational waves in the accumulated phase correction during the inspirals
among different scenarios for binary systems. On the light of the recent
results from GW170817 and the implications for the radius of
stars, our results show that hybrid stars can
only exist if a phase transition takes place at low densities close to
saturation
The three-dimensional noncommutative Gross-Neveu model
This work is dedicated to the study of the noncommutative Gross-Neveu model.
As it is known, in the canonical Weyl-Moyal approach the model is inconsistent,
basically due to the separation of the amplitudes into planar and nonplanar
parts. We prove that if instead a coherent basis representation is used, the
model becomes renormalizable and free of the aforementioned difficulty. We also
show that, although the coherent states procedure breaks Lorentz symmetry in
odd dimensions, in the Gross-Neveu model this breaking can be kept under
control by assuming the noncommutativity parameters to be small enough. We also
make some remarks on some ordering prescriptions used in the literature.Comment: 10 pages, IOP article style; v3: revised version, accepted for
publication in J. Phys.
Dressing approach to the nonvanishing boundary value problem for the AKNS hierarchy
We propose an approach to the nonvanishing boundary value problem for
integrable hierarchies based on the dressing method. Then we apply the method
to the AKNS hierarchy. The solutions are found by introducing appropriate
vertex operators that takes into account the boundary conditions.Comment: Published version Proc. Quantum Theory and Symmetries 7
(QTS7)(Prague, Czech Republic, 2011
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