The Accurate Modification of Tunneling Radiation of Fermions with Arbitrary Spin in Kerr-de Sitter Black Hole Space-time

The quantum tunneling radiation of fermions with arbitrary spin at the event horizon of Kerr-de Sitter black hole is accurately modified by using the dispersion relation proposed in the study of string theory and quantum gravitational theory. The derived tunneling rate and temperature at the black hole horizons are analyzed and studied.


Introduction
Lorentz dispersion relation has been regarded as the basic relation of modern physics, which is related to general relativity and quantum field theory. However, the development of quantum gravity theory shows that Lorentz relation must be modified in the high energy field. e dispersion relation theory in the high-energy field has not been established and needs to be further studied. Nevertheless, it is generally believed that the magnitude of such correction is only the Planck scale [1][2][3][4][5][6][7][8][9][10]. e dynamical equation of the spin-1/2 fermion is the Dirac equation in curved space-time, while that of spin-3/2 fermion is described by the Rarita-Schwinger equation in curved space-time. In 2007, Kerner and Mann et al. proposed to study the quantum tunneling of spin-1/2 fermion using semiclassical theories and methods [11,12]. Subsequently, Yang and Lin studied the quantum tunneling of fermions and bosons applying the semiclassical Hamilton-Jacobi method, and found that the behaviours of fermions and bosons could both be described by one same equation-Hamilton-Jacobi equation, and studied the quantum tunneling radiation of various black holes with the Hamilton-Jacobi theory and method [13,14]. In the process of studying the thermodynamics of black holes, it is worth mentioning that Banerjee and Majhi et al. put forward Hamilton-Jacobi method beyond the semiclassical approximation to modify the quantum tunnelling of bosons and fermions, and then studied the temperature, entropy, and other physical quantities of black holes [15,16]. Zhao et al. conducted effective research on Hawking radiation of various black holes [17][18][19]. What is worth studying is that Parikh and Wilczek corrected the particle tunneling rate at the event horizon of the black hole by taking into account the special and real situation that the background space-time changes before and a er particle tunneling [20]. Banerjee and Majhi et al. Further developed the mechanism of quantum tunneling through chirality method and semiclassical approximation [21][22][23][24][25]. Other scholars have also conducted a series of effective studies on the quantum tunneling rate and entropy of various black holes [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. Science and technology are always developing and progressing with the passage of time. e research on theoretical physics, astrophysics and related hot topics can always promote the continuous improvement of scientific research and bring about knowledge innovation. Recent studies show that the modification of Lorentz dispersion relation is necessary to modify the particle dynamical equation in the space-time of strong gravitational field, which is mainly to correct the quantum tunneling of fermions or bosons at the event horizon of the black hole, as well as the gravitational wave equation in curved space-time can also be modified as necessary. e purpose of this paper is to analyze the physical quantities, such as quantum tunneling rate of arbitrary spin fermions, black hole temperature, and black hole entropy in Kerr-de Sitter black hole space-time. erefore, in Section 2, the Rarita-Schwinger equation, which is the dynamical equation of arbitrary spin fermions, will be modified by applying the modified Lorenz dispersion relation. In Section 3 the quantum tunneling radiation of arbitrary spin fermions at horizons of Kerr-de Sitter black hole, which is a rotating, stationary, axisymmetric, and with a cosmic horizon black hole, is studied. Section 4 includes some conclusions and discussions.

From the Rarita-Schwinger Equation in Flat
Space-Time to the Rarita-Schwinger Equation in Curved Space-Time A modified dispersion relation on the quantum scale is given by [1][2][3][4][5][6][7][8][9][10] Consider the special case of the modified dispersion relation (the speed of light in vacuum equals unit in the notations), where 0 and are the energy and momentum of particle and is a constant on the Planck scale. When considering 훼 = 2, the dynamical equation of the spin-1/2 fermion is known as the Dirac equation. In flat space-time it is expressed as In flat space-time, the more general fermion dynamical equation was expressed by Rarita-Schwinger as [44] which satisfies the conditions of For the correction on quantum scale, take as a small correc- matrix Equation (8)  where is the radius of curvature of the cosmic horizon. Obviously, the event horizon and the cosmic horizon of this black hole satisfy the equation, respectively, as From (11), (12), and (13), we can get where is the energy and is a component of the generalized angular momentum of the particles tunneling from the black hole. e electromagnetic potential of the particles 퐴 = 0 in this space-time can also be known from expression (11). To solve the matrix Equation (9), suppose Substituting formulas (14) and (15) into Equation (9), and Equation (9) is simplified as From Equation (16) we can obtain From Equations (17), (18), and (6) (11) and (12). is is a precisely modified particle dynamical equation. When the correction term is ignored, the equation reverts to the Hamilton-Jacobi equation for particles of mass m in curved space-time expressed in Equations (11) and (12). erefore, we can think of Equation (25) as the modified Rarita-Schwinger equation. e process of solving Equation (25) is the process of solving Equation (9). We only need to solve Equation (25) to find the fermion action and consequently study the characteristics of quantum tunneling radiation at the horizons of the black hole.

Tunneling Radiation Characteristics of Arbitrary Spin Fermions in Kerr-de Sitter Black Hole Space-Time
From Equations (11) and (12), the values of metric determinant and the nonzero components of the contravariant metric tensor of the space-time can be calculated, respectively, as (19)

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According to the theory of tunneling radiation of the black hole, Equation (34) shows that the quantum tunneling radiation rate of the black hole is where is modified Hawking temperature at event horizon, expressed as where 0 is the unmodified Hawking temperature at the event horizon of the black hole. If we ignore the terms a er , It is worth noting that Equation (36) is an accurate correction based on the Lorenz dispersion relation. is is a modification of the specific theoretical basis, and a small modification on the quantum scale. Since the result of this correction will lead to the correction of black hole entropy, which is related to the information of black hole, the physical significance of this correction is worth studying deeply. e equation satisfying the cosmic horizon of the black hole is shown in (13). Similarly, by solving the dynamical equation of the arbitrary spin fermions in the space-time of the black hole, we can obtain the fermions tunneling rate at the cosmic horizon of the black hole. Similarly, we can get the Hawking temperature at the cosmic horizon of the black hole, which is expressed as where ὔ 0 and ὔ 0 can be got by changing in 0 and 0 into respectively. e difference between getting formula (37) and formula (36) is that when we integrate 휕푆 휕푟 ᐈ ᐈ ᐈ ᐈ ᐈ푟→푟 using the residue theorem, we need to integrate from to the inner where the researcher locates. In other words, 휕푆 휕푟 ᐈ ᐈ ᐈ ᐈ ᐈ푟→푟 and 휕푆 휕푟 ᐈ ᐈ ᐈ ᐈ ᐈ푟→푟 integrate in opposite directions.
Another important physical quantity in black hole thermodynamics is black hole entropy, and the modified Hawking temperature will lead to the modification of black hole entropy. According to the first law of thermodynamics of black holes, the entropy of black holes can be expressed as For the Kerr-de Sitter black hole, therefore, through formula (36), the modified entropy at the event horizon of the black hole is expressed as where, e positive and negative signs in Equation (32) correspond to the exit wave solution and the incident wave solution respectively. In order to find out the fermion action , we can consider the solution of equation Δ 푟 = 0 as a singularity, so we can integrate at the event horizon of the black hole by applying the residue theorem, and then we can obtain (29) number, so that the terms with O(ℏ) in fold equation is ignored. If we consider the effect from O(ℏ), the entropy of the black hole will be modified again, and the technology is developed in [15,16]. We will investigate the effect in future work.

Data Availability
No data were used to support this study.

Conflicts of Interest
e authors declare that they have no conflicts of interest regarding the publication of this paper.
Similarly, we can obtain the modified entropy at the cosmic horizon of the black hole, which is expressed as

Conclusion and Discussion
rough a series of calculations, the obtained formulas (35), (36), and (37) show that the tunneling radiation of arbitrary spin fermions in Kerr-de Sitter black hole space-time has been accurately modified based on the Lorenz dispersion theory.
e result of this correction shows that when its 푎 = 0, the related Hawking temperature at event horizon of black hole returns to the situation of static black hole, and when and 2 terms are further ignored, the tunneling rate, black hole temperature and other physical quantities return to the situation of Schwarzschild black hole. is further demonstrates the correctness of the conclusions. e conclusions of Equations (34)- (41) show that Lorenz dispersion relation is a theory worth studying in the field of high energy, and it also should be considered in the study of the theory of strong gravitational field and gravitational wave. e research on these topics can not only promote the research of quantum gravity theory, but also promote the innovation of theoretical physics and astrophysics knowledge.
Moreover, the above calculations show that the tunneling rate Γ depends on , , and 휔 0 = 훺 0 푗, but the back reaction from tunneling particles have not be considered. Now let's study the effect. A er the black hole emits a particle with energy and angular moment j, the mass and angular momentum of the black hole will become (푚 − 휔) and 퐽 − 푗 , and we have so the tunneling rate is rewritten as It means tunneling rate is dependent on the entropy of the black hole, so it is a candidate solution of the information loss paradox in black hole physics [45].
On the other hand, we do this work in semiclassical approximation, and in which ℏ is considered as a small