• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Cosmic acceleration with bulk viscosity in an anisotropic f(R,Lm) background

    2023-09-28 06:22:00RajaSolankiBinaPatelLakhanJaybhayeandSahoo
    Communications in Theoretical Physics 2023年7期

    Raja Solanki,Bina Patel,Lakhan V Jaybhaye and P K Sahoo,?

    1 Department of Mathematics,Birla Institute of Technology and Science-Pilani,Hyderabad Campus,Hyderabad-500078,India

    2 Department of Mathematical Sciences,P.D.Patel Institute of Applied Sciences,Charotar University of Science and Technology (CHARUSAT),Changa,Anand 388421,Gujarat,India

    Abstract

    In this article,we investigate the observed cosmic acceleration in the framework of a cosmological f(R,Lm) model dominated by bulk viscous matter in an anisotropic background.We consider the locally rotationally symmetric Bianchi type I metric and derive the Friedmann equations that drive the gravitational interactions in f(R,Lm) gravity.Further,we assume the functional form f (R,Lm)=+Lmα,where α is a free model parameter,and then fnid the exact solutions of feild equations corresponding to our viscous matter dominated model.We incorporate the updated H(z)data and the Pantheon data to acquire the best-fit values of parameters of our model by utilizing the χ2 minimization technique along with the Markov Chain Monte Carlo random sampling method.Further,we present the behavior of physical parameters that describe the Universe’s evolution phase,such as density,effective pressure and EoS parameters,skewness parameter,and the statefinder diagnostic parameters.We find that the energy density indicates expected positive behavior,whereas the negative behavior of bulk viscous pressure contributes to the Universe’s expansion.The effective EoS parameter favors the accelerating phase of the Universe’s expansion.Moreover,the skewness parameter shows the anisotropic nature of spacetime during the entire evolution phase of the Universe.Finally,from the statefinder diagnostic test,we found that our cosmological f(R,Lm)model lies in the quintessence region,and it behaves like a de-Sitter universe in the far future.We analyze different energy conditions in order to test the consistency of the obtained solution.We find that all energy conditions except strong energy condition (SEC) show positive behavior,while the violation of SEC favors the recently observed acceleration with the transition from decelerated to an accelerated epoch of the Universe’s expansion in the recent past.

    Keywords: LRS Bianchi type I metric,f(R,Lm) gravity,bulk viscosity,skewness parameter,equation of state parameter,statefinder parameter

    1.Introduction

    The universe in the beginning and future may have anisotropies despite the widely accepted assumption that the current universe is homogeneous and isotropic.In 1992,cosmic background explorer [1] revealed that the cosmic microwave background possesses a small amount of anisotropy at cosmological scales.The observational evidence,such as Wilkinson microwave anisotropy probe experiments [2] and cosmic background imager [3],strongly support this anisotropic nature of spacetime geometry.In 1998,the supernovae cosmology project led by Perlmutter and Riess confirmed the accelerating behavior of the Universe’s expansion [4,5].Moreover,recent advancements indicate the variations in the strengths of microwaves received from different directions,i.e.the Universe’s expansion is anisotropic [6].One can efficiently describe the homogeneous and anisotropic nature of spacetime using Bianchi-type cosmology.Several models based on Bianchi cosmology have appeared in the literature[7-13].In the present work,we incorporate locally rotationally symmetric(LRS)Bianchi type-I metric that is near to the Friedmann-Lema?tre-Robertson-Walker (FLRW) metric and can be considered as a generalization of the isotropic one.

    It is well known that the modified theories of gravity are capable of bypassing the undetected dark energy issue.The cosmological models based on the modifications of the Einstein action of general relativity that are obtained by introducing the function f(R) of the Ricci curvature R,first appeared in[14-16].This cosmological model could describe the observed cosmic expansion without incorporating any dark energy component[17,18].Observational characteristics of f(R)gravity models,along with the constraints acquired by the equivalence principle and solar system tests,are investigated in the references [19-23].The viable f(R) gravity models in the perspective of solar system tests do exist[24-26].Odintsov et al have studied energy conditions and the H0tension in the context of f(R)gravity models[27,28].One can follow references[29-35]to review some viable f(R)gravity models.

    Bertolami et al [36] introduced a generalization of the f(R) modified gravity by assuming an explicit coupling between the generic f(R) function of the Ricci curvature scalar R and the Lagrangian density of matter Lm,in the Einstein-Hilbert action.T Harko and F S N Lobo further extended this model to the case of arbitrary geometry-matter couplings [37].The cosmological models incorporating the non-minimal curvature and matter couplings present some interesting applications in cosmology and astrophysics[38-40].Further,T Harko and F S N Lobo proposed[41]f(R,Lm) gravity,which is the set of all curvature-matter coupling theories.In this modified gravity,the energy-momentum tensor has the non-vanishing covariant divergence,an extra force orthogonal to four velocities arises,and the motion of the test particle is non-geodesic.Moreover,the f(R,Lm)modified theory of gravity does not satisfy the equivalence principle,and it is constrained by the solar system tests[42,43].Nowadays,plenty of interesting cosmological implications of f(R,Lm) gravity theory started appearing in the literature; for instance,check references [44-50].

    In this manuscript,we investigate the bulk viscous matter dominated f(R,Lm) cosmological model with the anisotropic background.The significance of viscosity coefficients in cosmological modeling has a long history.From the hydrodynamics perspective,whenever a system loses its thermal equilibrium state,an effective pressure is generated to retrieve its thermal stability.Bulk viscosity in a matter content of the cosmos can be viewed as a manifestation of such an effective pressure.We aim to investigate the impact on the evolution phase of the Universe when we consider the effect of bulk viscosity coefficient ζ in the usual cosmic pressure.We assume that the coefficient of viscosity ζ obeys a scaling law,and that reduces the Einstein case to a form proportional to the Hubble parameter[51].This scaling law considered in our study is quite useful.One can follow references to review some attractive cosmological models incorporating the viscosity in cosmic fluid [52-58].

    The present work is organized as follows.In section 2,we present the fundamental formulations of f(R,Lm) gravity.In section 3,we derive the field equations corresponding to the LRS Bianchi type I metric.Further,we consider a cosmological f(R,Lm) model and then obtain the Hubble parameter value in terms of cosmic redshift.In section 4,we utilize the H(z) and Pantheon observational data to estimate the model and bulk viscous parameter values.In the next section 5,we present the physical behavior of cosmological parameters and statefinder diagnostic corresponding to the values of parameters obtained by the H(z),Pantheon,and H(z)+Pantheon data.In addition,in section 6,we investigate the different energy conditions.Finally,in section 7,we discuss and conclude our results.

    2.f(R,Lm) gravity theory

    The action ruling the gravitational interactions in f(R,Lm)gravity is given as

    Here f(R,Lm)is the generic function of the Ricci curvature R and the matter Lagrangian Lm.

    The Ricci curvature term R can be obtained by the following contraction,

    where Rμνis the Ricci tensor and it is defined as

    with Γβγαdenoting the components of Levi-Civita connection.

    One can obtain the following field equation of f(R,Lm)gravity by varying the action (1) with respect to the metric gμν,

    One can acquire the following relation by contracting the field equation (4)

    Here R,T,and Lmbeing the Ricci curvature scalar,energy-momentum scalar,and the matter Lagrangian term respectively.Furthermore,for any scalar function F.

    Moreover,by employing the covariant derivative in equation (4) one can obtain the following relation

    3.The cosmological f(R,Lm) model with anisotropic background

    Taking into account anomalies found in the observations of CMB,we consider following the LRS Bianchi type-I metric to describe the spatially homogeneous and anisotropic nature of the Universe

    where A(t) and B(t) are time dependent metric potentials.In particular,one can recover the usual flat FLRW background for A(t)=B(t)=a(t).Now,for the line element (8),we obtained the Ricci scalar as

    The stress-energy tensor characterizing the Universe filled with viscous content reads as

    The assumption of viscous effects in the cosmic fluid content can be viewed as an attempt to refine its description,relaxing its ideal properties and contributing negatively to the total pressure that can drive the aforementioned cosmic latetime acceleration.This can be checked in [59-61].

    The field equations governing the dynamics of the viscous matter dominated universe in f(R,Lm) with anisotropic background reads as

    Here δ is a measure of deviation from isotropy along y and z axes,called the skewness parameter.

    In this work,we study the following f(R,Lm) model in order to explore the cosmological implications of the f(R,Lm)gravity [62,63],

    where α is an arbitrary parameter.The cosmological f(R,Lm)model that we have considered is motivated by the generic function f(R,Lm)=f1(R)+f2(R)G(Lm) that represents arbitrary curvature-matter coupling [63].In particular,for α=1 one can obtain the usual Friedmann equations of GR.

    Now one can acquire the spatial volume element as

    Then by using (15),the mean value of the Hubble parameter can be calculated as

    Further,we consider an extra ansatz to obtain the exact solution of the field equations.We consider a physical relation between the expansion scalar θ and shear scalar σ,specifically,θ2∝σ2.In particular,for=constant,one can retrieve the isotropy of Hubble expansion[64].This gives rise to a following relation

    and the corresponding directional Hubble parameter can be obtained as

    For n=1,one can recover the usual flat FLRW cosmology.

    Now,for the specific function (14) with Lm=ρ[65],we obtained the following Friedmann equations for a non-relativistic viscous matter dominated universe,by using equations (11)-(13)

    By using equations (19) and (20),we obtain following first-order equation

    Figure 1.The 1?σ and 2?σ contour plot for the model parameters using the H(z) data set.

    On integrating the above equation,we have

    HereHy(0)=Hy0.Now by using equations (16) and(18),we obtained the average value of the Hubble parameter as

    By using equations (24) in (23),we obtained the expression for averaged Hubble parameter in terms of redshift as

    where H(0)=H0is the present value of the Hubble parameter.

    4.Observational constraints

    In this section,we are going to investigate the viability of our theoretical model by utilizing observational data sets.In this work,we incorporate updated H(z)data sets and the Pantheon supernovae observations.In order to perform statistical analysis,we use the χ2minimization technique along with the Markov Chain Monte Carlo random sampling method in the emcee python library [66].

    Figure 2.The 1?σ and 2?σ contour plot for the model parameters using the Pantheon data set.

    4.1.H(z) datasets

    It is well known that the expansion of the Universe can be characterized by the Hubble parameter.For early passively evolving galaxies,one can recover the Hubble parameter values by measuring the dt at a definite redshift value.In this work,we use 57 points of H(z) data in the redshift range 0.07 ≤z ≤2.41 [67].Moreover,there are two well-known approaches to extracting the values of the Hubble parameter,namely the differential age and line of sight baryonic acoustic oscillations method.The set of 57 H(z) data points can be checked in the reference [68,69].Now,the chi-square function corresponding to H(z) data points reads as

    where,the theoretically predicted value of the H(z) is denoted by Hthwhereas Hobsrepresents the observed value of H(z)with standard errorσH(zk).The contour plot for the model parameters α,ζ,n,and H0corresponding to H(z)data sets at 1?σ and 2?σ confidence intervals is presented in figure 1.

    The obtained best fti values areα=,ζ=,n=0.195±0.096,and H0=66.499±0.097.

    4.2.Pantheon datasets

    In this work,we incorporate 1048 points of Pantheon supernovae samples with corresponding distance moduli μobsin the redshift range z ?[0.01,2.3] [70].The χ2function corresponding to Pantheon data sets is given as

    Figure 3.The 1?σ and 2?σ contour plot for the model parameters using the H(z)+Pantheon data set.

    Here CSNdenotes the covariance matrix [70],and

    is the difference between the value of distance modulus obtained from the cosmological observations and its theoretically predicted values estimated from the given model with parameter space θ.One can estimate the distance modulus by using the relation μ=mB?MB,where mBand MBare the observed apparent magnitude and the absolute magnitude at a given redshift(Retrieving the nuisance parameter following the recent approach called BEAMS with Bias Correction [71]).Moreover,its theoretical value can be calculated as

    where

    The contour plot for the model parameters α,ζ,n,and H0corresponding to Pantheon data sets at 1?σ and 2?σ confidence interval is presented in figure 2.

    The obtained best fit values are α=0.899±0.098,ζ=179.99±0.10,n=0.196±0.098,and H0=66.498±0.097.

    4.3.H(z)+Pantheon datasets

    The χ2function to obtain the mean value of the model parameters corresponding to the combined H(z)+Pantheon data sets reads as

    Figure 4.Profile of the matter-energy density vs cosmic redshift z.

    Figure 5.Profile of the effective pressure vs cosmic redshift z.

    Figure 6.Profile of the skewness parameter vs cosmic redshift z.

    The contour plot for the model parameters α,ζ,n,and H0corresponding to H(z)+Pantheon data sets at 1?σ and 2?σ confidence interval is presented in figure 3.

    The obtained best fit values are α=0.895±0.098,ζ=180.007±0.099,n=0.195±0.099,and H0=66.50±0.10.

    Figure 7.Profile of the effective EoS vs cosmic redshift z.

    Figure 8.Profile of evolutionary trajectories of the given model in the r?s plane.

    5.Behavior of physical parameters

    In this section,we are going to present the behavior of physical parameters that describes the evolution phase of the Universe,corresponding to the extracted values of the model parameters from different observational data sets.

    The evolution profile of the matter-energy density and the effective pressure is presented in figures 4 and 5,respectively.We observe that the energy density indicates expected positive behavior,whereas pressure with viscosity coefficient shows negative behavior on the entire domain.Therefore the presence of the viscosity coefficient in the cosmic content contributes to the Universe’s expansion.The profile of the skewness parameter presented in figure 6 shows the anisotropic nature of the spacetime during the entire evolution phase of the Universe.Further,the effective EoS parameter presented in figure 7 favors the accelerating phase of the Universe’s expansion.Its present value corresponding to H(z),Pantheon,and combine H(z)+Pantheon data sets are ω0≈?0.9,ω0≈?0.85,and ω0≈?0.8 respectively.

    Figure 9.Profile of the null energy condition vs cosmic redshift z.

    The statefinder diagnostic proposed by V Sahni [72] can geometrically differentiate different models of dark energy through statefinder parameters which are defined as

    and

    The value (r>1,s<0) represents a phantom scenario whereas (r<1,s>0) denotes the quintessence type dark energy,and the value (r=1,s=0) mimics the standard ΛCDM model.The behavior of our f(R,Lm) model in the presence of viscous fluid in the r?s plane is presented in figure 8.The present values of statefinder parameters corresponding to H(z),Pantheon,and combine H(z)+Pantheon data sets are (r,s)=(0.87,0.06),(r,s)=(0.82,0.09),and (r,s)=(0.77,0.12) respectively [73].We found that our cosmological f(R,Lm) model lies in the quintessence region,and it behaves like the de-Sitter universe in the far future.

    6.Energy conditions

    In this section,we investigate different energy conditions in order to test the consistency of the obtained solution of our model.The energy conditions are relations imposed on the energy-momentum tensor in order to satisfy positive energy.The energy conditions are obtained from the well-known Raychaudhuri equation and are written as [74]

    ? Null energy condition (NEC): ρeff+peff≥0;

    ? Weak energy condition (WEC): ρeff≥0 and ρeff+peff≥0;

    Figure 10.Profile of the dominant energy condition vs cosmic redshift z.

    Figure 11.Profile of the strong energy condition vs cosmic redshift z.

    ? Dominant energy condition (DEC): ρeff±peff≥0;

    ? Strong energy condition (SEC): ρeff+3peff≥0,

    with ρeffbeing the effective energy density.

    The profile of the NEC and the DEC with respect to cosmic redshift is presented in figures 9 and 10,respectively.Since WEC is the combination of NEC and the positive energy density,we found that corresponding to the extracted values of the model parameters from different observational data sets,NEC,DEC,and WEC shows positive behavior,whereas SEC presented in figure 11 favors a transition from positive to negative behavior in the recent past.Thus,the violation of SEC strongly supports the recently observed acceleration with the transition from decelerated to the accelerated phase of the Universe’s expansion in the recent past.

    7.Conclusion

    From the hydrodynamics perspective,the assumption of viscous effects in the cosmic fluid is quite natural since the perfect fluid is,after all,an abstraction.In this work,we investigated the significance of viscosity coefficients to describe the observed cosmic acceleration by taking into account a cosmological f(R,Lm) model with an anisotropic background.We consideredf(R,Lm)=+Lmα,where α is an arbitrary parameter,with the effective equation of state=p-3ζHthat is the Einstein case value with proportionality constant ζ used in the Einstein theory [51].In section 3,we obtained the analytical expression of the Hubble parameter H(z)by incorporating the assumed f(R,Lm) viscous fluid model.Further,in section 4,we analyzed the viability of the assumed f(R,Lm) model by incorporating the observational data sets,specifically,H(z) data sets and the Pantheon supernovae data sets.The obtained best fit values areα=,ζ=,n=0.195±0.096,and H0=66.499±0.097 for the H(z) datasets,α=0.899±0.098,ζ=179.99±0.10,n=0.196±0.098,and H0=66.498±0.097 for the Pantheon datasets,and α=0.895±0.098,ζ=180.007±0.099,n=0.195±0.099,and H0=66.50±0.10 [75] for the combined H(z)+Pantheon datsets.In section 5,the behavior of some cosmological parameters has been presented.We observed that the energy density presented in figure 4 decreases with the expansion of the Universe,whereas the bulk viscous pressure presented in figure 5 indicates the negative behavior.The skewness parameter presented in figure 6 favors the anisotropic type evolution of the Universe during the entire time regime.Further,the effective EoS parameter in figure 7 shows the accelerating nature of the cosmic expansion with the present values ω0≈?0.9,ω0≈?0.85,and ω0≈?0.8 corresponding to H(z),Pantheon,and the combined H(z)+Pantheon data sets respectively.Finally,from figure 8 we found that our cosmological f(R,Lm) model exhibits quintessence behavior,and it favors the de-Sitter type expansion in the far future.In section 6,energy conditions have been analyzed to interpret the viability of the obtained solution.All energy conditions except SEC exhibit positive behavior (see figures 9 and 10),whereas the violation of SEC presented in figure 11 strongly supports the accelerating nature of cosmic expansion with the transition from decelerated to accelerated era.

    Acknowledgments

    R S acknowledges UGC,New Delhi,India for providing Senior Research Fellowship(UGC-Ref.No.:191620096030).L V J acknowledges UGC,Govt.of India,New Delhi,for awarding JRF (NTA Ref.No.: 191620024300).PKS acknowledges the Science and Engineering Research Board,Department of Science and Technology,Government of India for financial support to carry out Research Project No.:CRG/2022/001847 and IUCAA,Pune,India for providing support through the visiting Associateship program.We are very much grateful to the honourable referees and the editor for the illuminating suggestions that have significantly improved our research quality and presentation.

    ORCID iDs

    欧美另类一区| 最近手机中文字幕大全| 亚洲欧美激情在线| 亚洲国产看品久久| 男女之事视频高清在线观看 | 中文字幕人妻丝袜制服| 日韩精品有码人妻一区| 国产免费视频播放在线视频| 激情视频va一区二区三区| 亚洲国产毛片av蜜桃av| 成人毛片60女人毛片免费| 性少妇av在线| 又黄又粗又硬又大视频| 一个人免费看片子| 国产熟女欧美一区二区| 爱豆传媒免费全集在线观看| 99久久99久久久精品蜜桃| 欧美 日韩 精品 国产| 亚洲,欧美精品.| 天天躁夜夜躁狠狠久久av| 七月丁香在线播放| 不卡av一区二区三区| 伊人久久国产一区二区| 午夜福利免费观看在线| 桃花免费在线播放| 色婷婷久久久亚洲欧美| 精品人妻在线不人妻| 亚洲一码二码三码区别大吗| 777米奇影视久久| 美国免费a级毛片| 99久久人妻综合| 国产欧美亚洲国产| 久久精品久久久久久噜噜老黄| 日韩成人av中文字幕在线观看| 在线 av 中文字幕| 97人妻天天添夜夜摸| 老司机影院成人| 亚洲欧美一区二区三区国产| 婷婷成人精品国产| 丝袜喷水一区| 久久天堂一区二区三区四区| 国产精品.久久久| 国产成人精品久久久久久| 18在线观看网站| bbb黄色大片| 2018国产大陆天天弄谢| 精品少妇久久久久久888优播| 午夜福利视频精品| 啦啦啦中文免费视频观看日本| 免费久久久久久久精品成人欧美视频| 日本猛色少妇xxxxx猛交久久| 国产视频首页在线观看| 日日爽夜夜爽网站| 亚洲自偷自拍图片 自拍| 久久久久国产精品人妻一区二区| 欧美 日韩 精品 国产| 国产又爽黄色视频| 人妻一区二区av| 最近中文字幕2019免费版| 亚洲精品视频女| 男女下面插进去视频免费观看| 99香蕉大伊视频| 欧美日韩视频高清一区二区三区二| 韩国av在线不卡| 80岁老熟妇乱子伦牲交| 老鸭窝网址在线观看| 国产激情久久老熟女| 丝袜脚勾引网站| 欧美97在线视频| 国产成人精品久久二区二区91 | 亚洲精品中文字幕在线视频| 在线天堂中文资源库| 国产熟女午夜一区二区三区| 大片免费播放器 马上看| 日韩制服丝袜自拍偷拍| 黄频高清免费视频| av一本久久久久| 秋霞在线观看毛片| 亚洲成av片中文字幕在线观看| 久久性视频一级片| 午夜日韩欧美国产| 欧美精品高潮呻吟av久久| 精品免费久久久久久久清纯 | 老司机亚洲免费影院| 久久国产精品男人的天堂亚洲| 天堂中文最新版在线下载| 亚洲成国产人片在线观看| 亚洲自偷自拍图片 自拍| 美女午夜性视频免费| 永久免费av网站大全| 熟女少妇亚洲综合色aaa.| 水蜜桃什么品种好| www.av在线官网国产| 少妇人妻 视频| 99久久99久久久精品蜜桃| 精品亚洲成国产av| 制服丝袜香蕉在线| 男女边吃奶边做爰视频| 欧美成人午夜精品| 90打野战视频偷拍视频| 国产男女内射视频| 国产成人欧美| 一级毛片黄色毛片免费观看视频| 熟女少妇亚洲综合色aaa.| 少妇 在线观看| 亚洲,欧美精品.| 观看av在线不卡| 国产免费视频播放在线视频| 久久狼人影院| 国产 一区精品| 少妇猛男粗大的猛烈进出视频| 日日啪夜夜爽| 欧美精品一区二区大全| 最近中文字幕高清免费大全6| 纯流量卡能插随身wifi吗| 日韩熟女老妇一区二区性免费视频| 精品一区二区免费观看| 国产片特级美女逼逼视频| 男女高潮啪啪啪动态图| 别揉我奶头~嗯~啊~动态视频 | 久久天躁狠狠躁夜夜2o2o | 国产成人免费观看mmmm| 久久韩国三级中文字幕| 日韩中文字幕欧美一区二区 | 999久久久国产精品视频| 欧美黑人精品巨大| 岛国毛片在线播放| 精品久久蜜臀av无| 妹子高潮喷水视频| 亚洲中文av在线| 少妇人妻久久综合中文| 少妇人妻精品综合一区二区| 在线天堂中文资源库| 国产成人免费观看mmmm| 国产精品99久久99久久久不卡 | 亚洲欧美一区二区三区久久| av视频免费观看在线观看| 国产黄频视频在线观看| 午夜福利影视在线免费观看| 亚洲国产精品999| 亚洲一卡2卡3卡4卡5卡精品中文| 成年人午夜在线观看视频| 亚洲第一青青草原| 一级毛片 在线播放| 成年人午夜在线观看视频| 宅男免费午夜| 一级毛片 在线播放| 欧美精品亚洲一区二区| 99re6热这里在线精品视频| 日韩不卡一区二区三区视频在线| 国产精品久久久久成人av| 日韩欧美一区视频在线观看| 成人国产麻豆网| 国产精品久久久久成人av| 久久久欧美国产精品| 日韩一本色道免费dvd| 国产黄频视频在线观看| kizo精华| 午夜福利在线免费观看网站| 永久免费av网站大全| 亚洲免费av在线视频| 久久影院123| 国产精品嫩草影院av在线观看| 天堂俺去俺来也www色官网| 久久久久久人妻| 午夜福利乱码中文字幕| 最近中文字幕2019免费版| 久久久久精品久久久久真实原创| 人人澡人人妻人| 国产日韩欧美视频二区| 人妻 亚洲 视频| 天天操日日干夜夜撸| 又粗又硬又长又爽又黄的视频| 大片免费播放器 马上看| 亚洲专区中文字幕在线 | av又黄又爽大尺度在线免费看| 热re99久久国产66热| 在线亚洲精品国产二区图片欧美| 亚洲精品美女久久久久99蜜臀 | 亚洲欧洲精品一区二区精品久久久 | 欧美日韩一级在线毛片| 欧美日韩av久久| 亚洲精品美女久久av网站| 中国三级夫妇交换| 久久久久久人人人人人| 久久天躁狠狠躁夜夜2o2o | 国产爽快片一区二区三区| 亚洲欧美一区二区三区黑人| 久久韩国三级中文字幕| 蜜桃在线观看..| 亚洲国产av影院在线观看| 国产精品一区二区精品视频观看| 人人妻人人澡人人爽人人夜夜| 看非洲黑人一级黄片| 亚洲,一卡二卡三卡| 晚上一个人看的免费电影| www.av在线官网国产| 在线观看免费午夜福利视频| 中文字幕最新亚洲高清| 在线 av 中文字幕| 国产又爽黄色视频| 久久人妻熟女aⅴ| 各种免费的搞黄视频| 一级毛片我不卡| 极品少妇高潮喷水抽搐| 久久精品人人爽人人爽视色| 一区二区av电影网| 午夜福利视频精品| 99久久人妻综合| 99精国产麻豆久久婷婷| 99香蕉大伊视频| 亚洲精品av麻豆狂野| 久久久久久久国产电影| 制服丝袜香蕉在线| 亚洲婷婷狠狠爱综合网| 捣出白浆h1v1| 国产国语露脸激情在线看| 大片免费播放器 马上看| 亚洲伊人色综图| av有码第一页| 亚洲激情五月婷婷啪啪| 久久影院123| 丰满饥渴人妻一区二区三| 亚洲男人天堂网一区| 街头女战士在线观看网站| 黄色怎么调成土黄色| 女的被弄到高潮叫床怎么办| www.av在线官网国产| 日韩精品有码人妻一区| 中文字幕高清在线视频| av线在线观看网站| 亚洲成色77777| e午夜精品久久久久久久| 一区二区三区乱码不卡18| 嫩草影视91久久| 男的添女的下面高潮视频| 久久国产亚洲av麻豆专区| 国产av一区二区精品久久| 亚洲欧洲国产日韩| 亚洲成人一二三区av| 国产福利在线免费观看视频| 9191精品国产免费久久| 日韩 欧美 亚洲 中文字幕| 日韩熟女老妇一区二区性免费视频| 亚洲精品国产av蜜桃| 午夜福利免费观看在线| 亚洲av男天堂| 亚洲自偷自拍图片 自拍| 日韩 欧美 亚洲 中文字幕| 亚洲国产欧美一区二区综合| 国产精品 欧美亚洲| 国产激情久久老熟女| 亚洲精品第二区| 亚洲国产看品久久| 国产女主播在线喷水免费视频网站| 可以免费在线观看a视频的电影网站 | 在线 av 中文字幕| 精品人妻在线不人妻| 欧美亚洲 丝袜 人妻 在线| 人人妻人人添人人爽欧美一区卜| 国产成人欧美| 国产男女超爽视频在线观看| 国产精品亚洲av一区麻豆 | 中文天堂在线官网| 伦理电影免费视频| 啦啦啦啦在线视频资源| www.av在线官网国产| 亚洲综合色网址| 久久人人97超碰香蕉20202| 国产黄色免费在线视频| 热99国产精品久久久久久7| 看免费成人av毛片| 91老司机精品| 1024香蕉在线观看| 国产精品三级大全| 日韩 欧美 亚洲 中文字幕| 亚洲国产av新网站| 女的被弄到高潮叫床怎么办| 久久精品亚洲av国产电影网| 一二三四在线观看免费中文在| 人体艺术视频欧美日本| 亚洲 欧美一区二区三区| 国产精品国产av在线观看| 中国三级夫妇交换| 新久久久久国产一级毛片| 日本色播在线视频| 韩国av在线不卡| 永久免费av网站大全| 欧美乱码精品一区二区三区| 国产成人精品在线电影| 91精品伊人久久大香线蕉| kizo精华| 中文字幕最新亚洲高清| 少妇被粗大的猛进出69影院| 欧美中文综合在线视频| 国产亚洲av片在线观看秒播厂| av福利片在线| 久久久久久久大尺度免费视频| 这个男人来自地球电影免费观看 | 欧美亚洲 丝袜 人妻 在线| 男人爽女人下面视频在线观看| 99精国产麻豆久久婷婷| 午夜91福利影院| 国产探花极品一区二区| 综合色丁香网| 男女床上黄色一级片免费看| 国产精品女同一区二区软件| 纯流量卡能插随身wifi吗| 人妻 亚洲 视频| 国产又爽黄色视频| 天堂中文最新版在线下载| √禁漫天堂资源中文www| 精品国产超薄肉色丝袜足j| 免费高清在线观看日韩| 日韩大片免费观看网站| 亚洲欧洲精品一区二区精品久久久 | 日本av免费视频播放| 国产亚洲最大av| 毛片一级片免费看久久久久| 极品少妇高潮喷水抽搐| 国产精品熟女久久久久浪| 青春草视频在线免费观看| 中文欧美无线码| 久久精品国产综合久久久| 成年动漫av网址| 午夜av观看不卡| 亚洲精品日本国产第一区| 亚洲,欧美精品.| 日韩制服骚丝袜av| www日本在线高清视频| 99re6热这里在线精品视频| 国产麻豆69| 久久久久精品性色| 欧美在线一区亚洲| 国产精品99久久99久久久不卡 | 天堂俺去俺来也www色官网| 国产精品 国内视频| 免费日韩欧美在线观看| 亚洲国产精品一区二区三区在线| 亚洲一区中文字幕在线| 亚洲精品aⅴ在线观看| 超碰成人久久| 高清黄色对白视频在线免费看| 夜夜骑夜夜射夜夜干| 90打野战视频偷拍视频| 亚洲欧美一区二区三区久久| 国产熟女欧美一区二区| 亚洲四区av| 免费观看av网站的网址| 美国免费a级毛片| 国产高清不卡午夜福利| 国产在视频线精品| 亚洲七黄色美女视频| 女人爽到高潮嗷嗷叫在线视频| 久久久久久久久久久免费av| 精品国产国语对白av| 亚洲中文av在线| 啦啦啦在线免费观看视频4| 亚洲,欧美,日韩| 国产精品一区二区在线不卡| 欧美人与善性xxx| 久久综合国产亚洲精品| 日本黄色日本黄色录像| 中文字幕av电影在线播放| 99re6热这里在线精品视频| 久久综合国产亚洲精品| 亚洲国产日韩一区二区| av卡一久久| 90打野战视频偷拍视频| 美国免费a级毛片| 欧美日韩亚洲综合一区二区三区_| 欧美日韩国产mv在线观看视频| 国产免费现黄频在线看| 精品国产国语对白av| 夫妻性生交免费视频一级片| 一级毛片我不卡| 国产熟女欧美一区二区| 国产精品嫩草影院av在线观看| 最近最新中文字幕大全免费视频 | 巨乳人妻的诱惑在线观看| 日韩中文字幕视频在线看片| 一个人免费看片子| 亚洲精品国产一区二区精华液| 成年动漫av网址| www.精华液| 成人午夜精彩视频在线观看| 丰满迷人的少妇在线观看| 亚洲精华国产精华液的使用体验| 久久久久久久久免费视频了| 日韩,欧美,国产一区二区三区| av国产精品久久久久影院| 久久鲁丝午夜福利片| 一二三四中文在线观看免费高清| 欧美日韩综合久久久久久| 午夜91福利影院| 国产有黄有色有爽视频| a级毛片黄视频| 欧美精品人与动牲交sv欧美| 国产精品国产三级国产专区5o| 在线观看免费日韩欧美大片| 建设人人有责人人尽责人人享有的| a级毛片在线看网站| 亚洲五月色婷婷综合| 久久免费观看电影| 热re99久久精品国产66热6| 街头女战士在线观看网站| 国产一级毛片在线| 日韩精品有码人妻一区| 无遮挡黄片免费观看| 久久久久国产一级毛片高清牌| 日日啪夜夜爽| 成人三级做爰电影| kizo精华| 一区二区三区四区激情视频| 天天添夜夜摸| 老司机影院成人| 天天躁夜夜躁狠狠久久av| 韩国av在线不卡| 香蕉国产在线看| 飞空精品影院首页| 操美女的视频在线观看| 精品一区二区三卡| 成人18禁高潮啪啪吃奶动态图| 深夜精品福利| 黄色毛片三级朝国网站| 99国产综合亚洲精品| 最近手机中文字幕大全| 母亲3免费完整高清在线观看| 亚洲五月色婷婷综合| 国产一区二区三区av在线| 欧美 日韩 精品 国产| 久久久精品国产亚洲av高清涩受| 欧美精品高潮呻吟av久久| 国产精品免费大片| 午夜福利,免费看| 国精品久久久久久国模美| 免费高清在线观看日韩| 成年人午夜在线观看视频| 国产黄色免费在线视频| 女的被弄到高潮叫床怎么办| 国产成人免费观看mmmm| 午夜福利乱码中文字幕| 色视频在线一区二区三区| videosex国产| 免费在线观看视频国产中文字幕亚洲 | 精品亚洲乱码少妇综合久久| 大码成人一级视频| 赤兔流量卡办理| 精品第一国产精品| 国产成人精品在线电影| 国产老妇伦熟女老妇高清| 日韩人妻精品一区2区三区| 青春草国产在线视频| 亚洲一卡2卡3卡4卡5卡精品中文| 精品亚洲成a人片在线观看| 大码成人一级视频| 黄片小视频在线播放| 久久99热这里只频精品6学生| 成人免费观看视频高清| 大香蕉久久成人网| 悠悠久久av| 日韩制服骚丝袜av| 精品视频人人做人人爽| 国产成人av激情在线播放| 成人免费观看视频高清| www日本在线高清视频| 国产极品天堂在线| 国产成人欧美| 国产精品亚洲av一区麻豆 | 久久97久久精品| 99国产综合亚洲精品| 欧美日韩av久久| 欧美精品一区二区免费开放| 97在线人人人人妻| 多毛熟女@视频| 十八禁网站网址无遮挡| 日韩欧美精品免费久久| 久久天躁狠狠躁夜夜2o2o | www.av在线官网国产| 无限看片的www在线观看| 伊人亚洲综合成人网| 亚洲精品国产区一区二| 日韩精品有码人妻一区| 亚洲国产看品久久| 黄色怎么调成土黄色| 日韩,欧美,国产一区二区三区| 综合色丁香网| 美女高潮到喷水免费观看| 老司机深夜福利视频在线观看 | 男女免费视频国产| 国产无遮挡羞羞视频在线观看| 99久久精品国产亚洲精品| 国产精品香港三级国产av潘金莲 | 黄色 视频免费看| 最新在线观看一区二区三区 | 国产乱人偷精品视频| 亚洲欧美成人综合另类久久久| 婷婷成人精品国产| av福利片在线| 人人妻,人人澡人人爽秒播 | 亚洲精品日韩在线中文字幕| 一本久久精品| 国产av码专区亚洲av| netflix在线观看网站| 大香蕉久久网| 爱豆传媒免费全集在线观看| 少妇精品久久久久久久| 极品人妻少妇av视频| 午夜精品国产一区二区电影| 男人操女人黄网站| 亚洲精品中文字幕在线视频| 久久性视频一级片| 亚洲精品国产区一区二| 哪个播放器可以免费观看大片| 另类精品久久| 亚洲熟女精品中文字幕| 国产成人欧美| 99精品久久久久人妻精品| 丝袜在线中文字幕| 在线观看免费午夜福利视频| 999久久久国产精品视频| 亚洲欧洲国产日韩| 亚洲av在线观看美女高潮| 亚洲欧洲国产日韩| 亚洲精品一区蜜桃| 中国三级夫妇交换| 亚洲国产看品久久| 久久ye,这里只有精品| 免费在线观看完整版高清| 人人澡人人妻人| 国产在线视频一区二区| 久久99热这里只频精品6学生| 九草在线视频观看| 99久久99久久久精品蜜桃| 国产av码专区亚洲av| 亚洲四区av| 精品福利永久在线观看| 狂野欧美激情性bbbbbb| 国产精品成人在线| 欧美精品高潮呻吟av久久| 综合色丁香网| 高清黄色对白视频在线免费看| 美女视频免费永久观看网站| 成人三级做爰电影| 美女高潮到喷水免费观看| 国产精品久久久久久精品电影小说| 欧美日韩一级在线毛片| 一区二区日韩欧美中文字幕| 午夜日韩欧美国产| 汤姆久久久久久久影院中文字幕| 精品亚洲乱码少妇综合久久| 亚洲av电影在线观看一区二区三区| 欧美日韩综合久久久久久| 欧美成人午夜精品| 成人国语在线视频| 一本一本久久a久久精品综合妖精| 久久 成人 亚洲| 天堂中文最新版在线下载| 国产 精品1| 永久免费av网站大全| 亚洲免费av在线视频| 久久97久久精品| 51午夜福利影视在线观看| 韩国av在线不卡| 欧美日韩一级在线毛片| 极品少妇高潮喷水抽搐| 一级毛片 在线播放| 欧美97在线视频| 黑人欧美特级aaaaaa片| 女性生殖器流出的白浆| 久久精品亚洲熟妇少妇任你| 欧美精品人与动牲交sv欧美| 97精品久久久久久久久久精品| 超色免费av| 亚洲av综合色区一区| 国产欧美日韩综合在线一区二区| 人人妻,人人澡人人爽秒播 | 天堂中文最新版在线下载| 下体分泌物呈黄色| 国产精品成人在线| 十八禁高潮呻吟视频| 亚洲国产中文字幕在线视频| 尾随美女入室| 我的亚洲天堂| 19禁男女啪啪无遮挡网站| 在线观看国产h片| 19禁男女啪啪无遮挡网站| 老司机深夜福利视频在线观看 | 成年人午夜在线观看视频| 久久99精品国语久久久| 丝袜在线中文字幕| 久久这里只有精品19| 亚洲国产毛片av蜜桃av| 夫妻午夜视频| 欧美黄色片欧美黄色片| 男女边吃奶边做爰视频| 19禁男女啪啪无遮挡网站| a级毛片黄视频| 午夜福利网站1000一区二区三区| 久久久久国产精品人妻一区二区| 99香蕉大伊视频| 精品亚洲成国产av| 欧美少妇被猛烈插入视频| 成人免费观看视频高清| 国产精品嫩草影院av在线观看| 国产精品 国内视频| 晚上一个人看的免费电影| av又黄又爽大尺度在线免费看| 欧美人与善性xxx| 2021少妇久久久久久久久久久| 纵有疾风起免费观看全集完整版| 少妇人妻精品综合一区二区| 久久久精品国产亚洲av高清涩受| 精品亚洲成a人片在线观看| 亚洲国产中文字幕在线视频|