arXiv subjects
Publications and source records attributed to Zhan-Ying Yang.
By analysing the cosmological dynamical system with a dark-sector interaction which changes sign during the cosmological evolution, we find a scaling attractor to help to alleviate the cosmic-coincidence problem. This result shows that this interaction can bring new features to the cosmology.
In present paper, by using the generalized DDC formalism, we investigate the spontaneous excitation of an static atom interacting with electromagnetic vacuum fluctuations outside a EGB black hole in $d$-dimensions. We find that spontaneous excitation does not occur in Boulware vacuum. The Gauss-Bonnet term has no effect on the stability of the atom. Finally, we discuss the contribution of the coupling constant and dimensional factor to the results in three different kinds of spacetime.
In present paper, we investigated the quantization of an electromagnetic field in the background of static spherically symmetric d-dimensional spacetime in the Boulware vacuum. We have also calculated the response rate of a static charge outside both d-dimensional Schwarzschild black hole and the GB black hole in the low-frequency regime, which can be expressed as the summation of hypergeometric functions.
We study on rational solutions on nonzero background of coupled Sasa-Satsuma equations through Darboux transformation method, which take into account third order dispersion, the term with self-frequency shift, and the term describing self-steepening corrections to the cubic nonlinearity. We find there are some new types of localized waves in the coupled system, such as dark-antidark soliton pair, W-shaped soliton, dark W-shaped soliton, and the combined localized waves of them. The results indicate that there are abundant novel localized waves in the two-mode fiber with these high-order effects, which would inspire experimental realization in the related physical systems.
We investigate the localized waves of the coupled two-mode nonlinear Schrödinger equations with a pair-tunneling term representing strongly interacting particles can tunnel between the modes as a fragmented pair. Facilitated by Darboux transformation, we have derived exact solution of nonlinear vector waves such as bright solitons, Kuznetsov-Ma soliton, Akhmediev breathers and rogue waves and demonstrated their interesting temporal-spatial structures. The phase diagram that demarcates the parameter ranges of the nonlinear waves is obtained. Our results have implications in such diverse fields as Bose-Einstein condensate, nonlinear fibers and super fluids.
Interference patterns associated with soliton-soliton interaction are investigated in detail. We find that the temporal and spatial interference patterns exhibit quite different characteristics. The period of the spatial interference pattern is determined by the relative velocity of the solitons, and the temporal pattern behavior is determined by the peak amplitudes and the kinetic energy of the solitons. Analytical expressions for the periods of the interference patterns are obtained. A method for classifying the nonlinearity of many nonlinear systems is proposed. As an example, we discuss possibilities to observe these properties of solitons in a nonlinear planar waveguide.
We obtain the determinant representations of the scalar products for the XXZ Gaudin model with generic non-diagonal boundary terms.
We explore static spherically symmetric stars in the Gauss-Bonnet gravity without cosmological constant, and present an exact internal solution which attaches to the exterior vacuum solution outside stars. It turns out that the presence of the Gauss-Bonnet term with a positive coupling constant completely changes thermal and gravitational energies, and the upper bound of red shift of spectral lines from the surface of stars. Unlike in general relativity, the upper bound of red shift is dependent on the density of stars in our case. Moreover, we have proven that two theorems for judging the stability of equilibrium of stars in general relativity can be hold in Gauss-Bonnet gravity.
In present paper the gravitational effect of spontaneous symmetry breaking vacuum energy density is investigated by subtracting the flat space-time contribution from the energy in the curved space-time. We found that the remain effective energy-momentum tensor is too small to cause the acceleration of the universe although it satisfies the characteristic of the dark energy. However it could provide a promising explanation to the puzzle why the gravitational effect produced by the huge symmetry breaking vacuum energy in the electroweak theory has not been observed, since it has a sufficient small value (smaller than the observed cosmic energy density by a factor $10^{32}$).
With the help of the Drinfeld twist or factorizing F-matrix for the eight-vertex SOS model, we obtain the explicit determinant expression of the partition function of the eight-vertex model with a generic non-diagonal reflecting end and domain wall boundary condition. Our result shows that, contrary to the eight-vertex model without a reflection end, the partition function can be expressed as a single determinant.
This paper presents a new metric for slowly rotating charged Gauss-Bonnet black holes in higher dimensional anti-de Sitter spaces. Taking the angular momentum parameter $a$ up to second order, the slowly rotating charged black hole solutions are obtained by working directly in the action.
This paper presents a new metric and studies slowly rotating Gauss-Bonnet black holes with one nonvanishing angular momentum in five dimensional anti-de Sitter spaces. Taking the angular momentum parameter $a$ up to second order, the slowly rotating black hole solutions are obtained by working directly in the action. In addition, it also finds that this method is applicable in higher order Lovelock gravity.
We explore the gravitational collapse of a spherically symmetric dust cloud in the Einstein-Gauss-Bonnet gravity without a cosmological constant, and obtain three families of LTB-like solutions. It is shown that the Gauss-Bonnet term has a profound influence on the nature of singularities, and the global structure of space-time changes drastically from the analogous general relativistic case. Interestingly, the formation of a naked, massive and uncentral singularity, allowed in 5-dimensional space-time, is forbidden if $D\geq6$. Moreover, such singularity is gravitational strong and a serious counter example to CCH.
We investigate the spherically symmetric gravitational collapse of an incoherent dust cloud by considering a LTB type space-time in third order Lovelock Gravity without cosmological constant, and give three families of LTB-like solutions which separately corresponding to hyperbolic, parabolic and elliptic. Notice that the contribution of high order curvature corrections have a profound influence on the nature of the singularity, and the global structure of space-time changes drastically from the analogous general relativistic case. Interestingly, the presence of high order Lovelock terms leads to the formation of massive, naked and time-like singularities in the 7D space-time, which is disallowed in general relativity. Moveover, we point out that the naked singularities in the 7D case may be gravitational weak therefore may not be a serious threat to the cosmic censorship hypothesis, while the naked singularities in the $D\geq8$ inhomogeneous collapse violate the cosmic censorship hypothesis seriously.
With the help of the F-basis provided by the Drinfeld twist or factorizing F-matrix of the eight-vertex solid-on-solid (SOS) model, we obtain the determinant representations of the scalar products of Bethe states for the open XYZ chain with non-diagonal boundary terms. By taking the on shell limit, we obtain the determinant representations (or Gaudin formula) of the norms of the Bethe states.
We present a series of chirp-free and chirped analytical nonautonomous soliton solutions to the generalized nonlinear Schrodinger equation (NLSE) with distributed coefficients by Darboux transformation from a trivial seed. For chirpfree nonautonomous soliton, the dispersion management term can change the motion of nonautonomous soliton and do not affect its shape at all. Especially,the classical optical soliton can be presented with variable dispersion term and nonlinearity when there is no gain. For chirped nonautonomous soliton, dispersion management can affect the shape and motion of nonautonomous solitons meanwhile. The periodic dispersion term can be used to control its "breathing" shape, and it does not affect the trajectory of nonautonomous soliton center with a certain condition.
With the help of the Drinfeld twist or factorizing F-matrix for the eight-vertex solid-on-solid (SOS) model, we find that in the F-basis provided by the twist the two sets of pseudo-particle creation operators simultaneously take completely symmetric and polarization free form. This allows us to obtain the explicit and completely symmetric expressions of the two sets of Bethe states of the model.
In this paper, we present the asymptotically flat black hole solutions for arbitrary values of coefficients in third order Lovelock gravity, and then derive gravitational mass, Hawking temperature and entropy of the black holes. In addition, based on a Hamilton-Jacobi approach beyond the semiclassical approximation, we compute the corrected temperature and entropy of the third order Lovelock black holes in seven dimensional spacetimes. By considering the coefficients α2 = α and α3 = α2/3, we obtain a special black hole solution. Later, we perform the local and global stability analysis of the black holes with different horizon structures k = \pm1 for coefficient α2 < 0 and α2 > 0, respectively.