In this work,we use the most recent publicly available type Ⅰa supernova(SNIa) compilations and H(z) data.A well formulated cosmological model based on Bianchi type Ⅰ(BI) metric is implemented in the presence of the...In this work,we use the most recent publicly available type Ⅰa supernova(SNIa) compilations and H(z) data.A well formulated cosmological model based on Bianchi type Ⅰ(BI) metric is implemented in the presence of the Ricci dark energy model.Using the maximum likelihood technique,we estimate the present value of Hubble's constant H_(0)=70.339±0.743,matter density parameter Ω_(m_(0))=0.297±0.031,anisotropy parameter Ω_(σ_(0))=-0.004 01 ± 0.001 07 within 1σ′ confidence level by bounding our derived model with recent joint Pantheon and H(z)data.We have constrained the present value of the equation of state parameter as ω_(de)=-1.17 joint with the observational data.The present value of the deceleration parameter of the Universe in the derived model is obtained as q_(0)=-0.749_(-0.086)^(+0.076).Transition redshift is also derived as z_(tr)~0.551 with the recent observations(Pantheon+H(z)) datasets.Finally,we compare the anisotropy effects on the evolution of H(z) for the proposed model under consideration with different observational datasets.展开更多
这里说的并不是海顿的爸爸。海顿的爸爸只是奥地利农村的一位修车匠,对于他平庸的生活,史家们也做不了什么文章,只知道他在小海顿六岁时,不得不将他送到自己在维也纳的兄弟家中寄养。幸亏那叔父还懂些音乐,教了海顿一些乐理知识、歌唱...这里说的并不是海顿的爸爸。海顿的爸爸只是奥地利农村的一位修车匠,对于他平庸的生活,史家们也做不了什么文章,只知道他在小海顿六岁时,不得不将他送到自己在维也纳的兄弟家中寄养。幸亏那叔父还懂些音乐,教了海顿一些乐理知识、歌唱法和器乐演奏,两年之后又把这可怜的孩子送到唱诗班去了。而本文的主角正是后来成为大音乐家的海顿(Franz音乐封神榜海顿爸爸Pantheon of Music Papa Haydn文字_林华Joseph Haydn,1732-1809)。展开更多
To scrutinize the nature of dark energy,many equations of state have been proposed.In this context,we examine the simplest parameterization of the equation of state parameter of dark energy in an anisotropic Bianchi t...To scrutinize the nature of dark energy,many equations of state have been proposed.In this context,we examine the simplest parameterization of the equation of state parameter of dark energy in an anisotropic Bianchi type I universe compared with theΛCDM model.Using different combinations of data samples,including Pantheon and Pantheon+H(z),alongside applying the minimization of theχ^(2)function of the distance modulus of data samples,we obtain the constrained values of cosmographic parameters in the parameterization of the dark energy scenario.One condition of the phantom barrier crossing is acquired.Several physical properties of the universe are discussed by considering the anisotropy effect and different observational data points.One should note that the deductions of the cosmological parameter verify recent observational data.展开更多
文摘In this work,we use the most recent publicly available type Ⅰa supernova(SNIa) compilations and H(z) data.A well formulated cosmological model based on Bianchi type Ⅰ(BI) metric is implemented in the presence of the Ricci dark energy model.Using the maximum likelihood technique,we estimate the present value of Hubble's constant H_(0)=70.339±0.743,matter density parameter Ω_(m_(0))=0.297±0.031,anisotropy parameter Ω_(σ_(0))=-0.004 01 ± 0.001 07 within 1σ′ confidence level by bounding our derived model with recent joint Pantheon and H(z)data.We have constrained the present value of the equation of state parameter as ω_(de)=-1.17 joint with the observational data.The present value of the deceleration parameter of the Universe in the derived model is obtained as q_(0)=-0.749_(-0.086)^(+0.076).Transition redshift is also derived as z_(tr)~0.551 with the recent observations(Pantheon+H(z)) datasets.Finally,we compare the anisotropy effects on the evolution of H(z) for the proposed model under consideration with different observational datasets.
文摘这里说的并不是海顿的爸爸。海顿的爸爸只是奥地利农村的一位修车匠,对于他平庸的生活,史家们也做不了什么文章,只知道他在小海顿六岁时,不得不将他送到自己在维也纳的兄弟家中寄养。幸亏那叔父还懂些音乐,教了海顿一些乐理知识、歌唱法和器乐演奏,两年之后又把这可怜的孩子送到唱诗班去了。而本文的主角正是后来成为大音乐家的海顿(Franz音乐封神榜海顿爸爸Pantheon of Music Papa Haydn文字_林华Joseph Haydn,1732-1809)。
文摘To scrutinize the nature of dark energy,many equations of state have been proposed.In this context,we examine the simplest parameterization of the equation of state parameter of dark energy in an anisotropic Bianchi type I universe compared with theΛCDM model.Using different combinations of data samples,including Pantheon and Pantheon+H(z),alongside applying the minimization of theχ^(2)function of the distance modulus of data samples,we obtain the constrained values of cosmographic parameters in the parameterization of the dark energy scenario.One condition of the phantom barrier crossing is acquired.Several physical properties of the universe are discussed by considering the anisotropy effect and different observational data points.One should note that the deductions of the cosmological parameter verify recent observational data.
