Hydrodynamics is a general theoretical framework for describing the long-time large-distance behaviors of macroscopic physical systems.It has many important applications in various branches of physics,from cosmic expa...Hydrodynamics is a general theoretical framework for describing the long-time large-distance behaviors of macroscopic physical systems.It has many important applications in various branches of physics,from cosmic expansion and galaxy/star evolutions at the very large scales to relativistic nuclear collisions at the very small scales.The core of hydrodynamics is about physical quantities protected by exact conservation laws,such as energy,momentum and conserved charges.Past hydrodynamic studies almost entirely focus on the energy–momentum conservation and charge conservation.Only very recently,there has been a rapidly increasing interest in understanding the role of angular momentum conservation in the hydrodynamic context and its implications for spin transport of underlying constituents.展开更多
We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:...We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:a rotational suppression of the scalar-channel condensates,in particular,the pion condensation region;and a rotational enhancement of the rho condensation region with vector-channel condensate.A new phase diagram for isospin matter under rotation is mapped out on the ω−μI plane where the three distinct phases,corresponding to the σ,π,ρ-dominated regions,respectively,are separated by a second-order line at low isospin chemical potential as well as a first-order line at high rotation and are further connected at a tri-critical point.展开更多
We study the mass spectra and decay process of σ and π_(0) mesons under a strong external magnetic field.To achieve this goal,we deduce the thermodynamic potential in a two-flavor,hot and magnetized Nambu-Jona-Lasin...We study the mass spectra and decay process of σ and π_(0) mesons under a strong external magnetic field.To achieve this goal,we deduce the thermodynamic potential in a two-flavor,hot and magnetized Nambu-Jona-Lasinio model.We calculate the energy gap equation through the random phase approximation(RPA).Then we use the Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B.Our results indicate that the magnetic field has little influence on the mass of π_(0) at low temperatures.However,for quarks andσmesons,their mass clearly changes,which reflects the influence of magnetic catalysis(MC).The presence of a magnetic field accelerates the decay of the meson while the presence of a chemical potential will decrease the decay process.展开更多
The solutions of the relativistic viscous hydrodynamics for longitudinally expanding fireballs are investig-ated with the Navier-Stokes theory and Israel-Stewart theory.The energy and the Euler conservation equations ...The solutions of the relativistic viscous hydrodynamics for longitudinally expanding fireballs are investig-ated with the Navier-Stokes theory and Israel-Stewart theory.The energy and the Euler conservation equations for the viscous fluid are derived in Rindler coordinates,by assuming that the longitudinal expansion effect is small.Under the perturbation assumption,an analytical perturbation solution for the Navier-Stokes approximation and numerical solutions for the Israel-Stewart approximation are presented.The temperature evolution with both shear viscous ef-fect and longitudinal acceleration effect in the longitudinal expanding framework are presented.The specific temper-ature profile shows symmetric Gaussian shape in the Rindler coordinates.Further,we compare the results from the Israel-Stewart approximation with the results from the Bjorken and the Navier-Stokes approximations,in the pres-ence of the longitudinal acceleration expansion effect.We found that the Israel-Stewart approximation gives a good description of the early stage evolutions than the Navier-Stokes theory.展开更多
According to gauge/gravity duality,we use an Einstein-Maxwell-dilaton(EMD)model to study the running coupling constant at finite chemical potential and magnetic field.First,we calculate the effect of temperature on th...According to gauge/gravity duality,we use an Einstein-Maxwell-dilaton(EMD)model to study the running coupling constant at finite chemical potential and magnetic field.First,we calculate the effect of temperature on the running coupling constant and find the results are qualitatively consistent with lattice guage theory.Subsequently,we calculate the effect of chemical potential and magnetic field on running coupling.It is found that the chemical potential and magnetic field both suppress the running coupling constant.However,the effect of the magnetic field is slightly larger than that of chemical potential for a fixed temperature.Compared with the confinement phase,the magnetic field has a large influence on the running coupling in the deconfinement phase.展开更多
In our previous work [1], a new kind of inflation model was proposed, which has the interesting property that its perturbation equation of motion gets a correction of k4, due to the non-linearity of the kinetic term.N...In our previous work [1], a new kind of inflation model was proposed, which has the interesting property that its perturbation equation of motion gets a correction of k4, due to the non-linearity of the kinetic term.Nonetheless, the scale-invariance of the power spectrum remains valid, both in large-k and small-k limits. In this paper, we investigate in detail the spectral index, the index running and the tensor/scalar ratio in this model, especially in the potential-driven case, and compare the results with the current PLANCK/BICEP observational data.We also discuss the tensor spectrum in this case, which is expected to be tested by future observations of primordial gravitational waves.展开更多
基金supported in part by the National Natural Science Foundation of China (11735007, 11890711, 11890710, 12275104, and 12205309)the China Scholarship Council (201906770027)+2 种基金the Fundamental Research Funds for the Central Universitiesby the NSF (PHY-2209183)the U.S. Department of Energy, Office of Science, Office of Nuclear Physics,within the framework of the Beam Energy Scan Theory (BEST) Topical Collaboration
文摘Hydrodynamics is a general theoretical framework for describing the long-time large-distance behaviors of macroscopic physical systems.It has many important applications in various branches of physics,from cosmic expansion and galaxy/star evolutions at the very large scales to relativistic nuclear collisions at the very small scales.The core of hydrodynamics is about physical quantities protected by exact conservation laws,such as energy,momentum and conserved charges.Past hydrodynamic studies almost entirely focus on the energy–momentum conservation and charge conservation.Only very recently,there has been a rapidly increasing interest in understanding the role of angular momentum conservation in the hydrodynamic context and its implications for spin transport of underlying constituents.
基金supported by the Ministry of Science and Technology of China (MSTC) under the"973"(2015CB856904(4))by NSFC (11735007)+3 种基金by NSF (PHY-1352368,PHY-1913729)by the U.S. Department of Energy,Office of Science,Office of Nuclear Physics,within the framework of the Beam Energy Scan Theory (BEST)Topical Collaborationpartial support from the China Scholarship Councilthe Institute for Advanced Study of Indiana University for partial support.
文摘We investigate mesonic condensation in isospin matter under rotation.Using the two-flavor NJL effective model in the presence of global rotation,we demonstrate two important effects of rotation on its phase structure:a rotational suppression of the scalar-channel condensates,in particular,the pion condensation region;and a rotational enhancement of the rho condensation region with vector-channel condensate.A new phase diagram for isospin matter under rotation is mapped out on the ω−μI plane where the three distinct phases,corresponding to the σ,π,ρ-dominated regions,respectively,are separated by a second-order line at low isospin chemical potential as well as a first-order line at high rotation and are further connected at a tri-critical point.
基金Supported by the National Natural Science Foundation of China(11735007,11890711,11890710)。
文摘We study the mass spectra and decay process of σ and π_(0) mesons under a strong external magnetic field.To achieve this goal,we deduce the thermodynamic potential in a two-flavor,hot and magnetized Nambu-Jona-Lasinio model.We calculate the energy gap equation through the random phase approximation(RPA).Then we use the Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B.Our results indicate that the magnetic field has little influence on the mass of π_(0) at low temperatures.However,for quarks andσmesons,their mass clearly changes,which reflects the influence of magnetic catalysis(MC).The presence of a magnetic field accelerates the decay of the meson while the presence of a chemical potential will decrease the decay process.
基金Supported by the Ministry of Science and Technology of China(MSTC)under the"973"Project No.2015CB856904(4),NSFC(11735007,11890711)the Sino-Hungarian bilateral Cooperation Program(Te'T 12CN-1-2012-0016)D.She is Supported by the China Scholarship Council(CSC)(201906770027)。
文摘The solutions of the relativistic viscous hydrodynamics for longitudinally expanding fireballs are investig-ated with the Navier-Stokes theory and Israel-Stewart theory.The energy and the Euler conservation equations for the viscous fluid are derived in Rindler coordinates,by assuming that the longitudinal expansion effect is small.Under the perturbation assumption,an analytical perturbation solution for the Navier-Stokes approximation and numerical solutions for the Israel-Stewart approximation are presented.The temperature evolution with both shear viscous ef-fect and longitudinal acceleration effect in the longitudinal expanding framework are presented.The specific temper-ature profile shows symmetric Gaussian shape in the Rindler coordinates.Further,we compare the results from the Israel-Stewart approximation with the results from the Bjorken and the Navier-Stokes approximations,in the pres-ence of the longitudinal acceleration expansion effect.We found that the Israel-Stewart approximation gives a good description of the early stage evolutions than the Navier-Stokes theory.
基金X.C.is supported by the Research Foundation of Education Bureau of Hunan Province,China(21B0402)L.Z.is supported in part by the Fundamental Research Funds for the Central Universities.D.H.is in part supported by the National Natural Science Foundation of China(11735007,11890711)。
文摘According to gauge/gravity duality,we use an Einstein-Maxwell-dilaton(EMD)model to study the running coupling constant at finite chemical potential and magnetic field.First,we calculate the effect of temperature on the running coupling constant and find the results are qualitatively consistent with lattice guage theory.Subsequently,we calculate the effect of chemical potential and magnetic field on running coupling.It is found that the chemical potential and magnetic field both suppress the running coupling constant.However,the effect of the magnetic field is slightly larger than that of chemical potential for a fixed temperature.Compared with the confinement phase,the magnetic field has a large influence on the running coupling in the deconfinement phase.
基金Supported by NSFC(11405069,11653002,11735007,111375070)
文摘In our previous work [1], a new kind of inflation model was proposed, which has the interesting property that its perturbation equation of motion gets a correction of k4, due to the non-linearity of the kinetic term.Nonetheless, the scale-invariance of the power spectrum remains valid, both in large-k and small-k limits. In this paper, we investigate in detail the spectral index, the index running and the tensor/scalar ratio in this model, especially in the potential-driven case, and compare the results with the current PLANCK/BICEP observational data.We also discuss the tensor spectrum in this case, which is expected to be tested by future observations of primordial gravitational waves.
