We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parame...We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parameter E(z)from the DESI BAO Alcock-Paczynski(AP)data using Gaussian process to perform the null test.We find strong evidence of accelerated expansion from the DESI BAO AP data.By reconstructing the deceleration parameter q(z) from the DESI BAO AP data,we find that accelerated expansion persisted until z■0.7 with a 99.7%confidence level.Additionally,to provide insights into the Hubble tension problem,we propose combining the reconstructed E(z) with D_(H)/r_(d) data to derive a model-independent result r_(d)h=99.8±3.1 Mpc.This result is consistent with measurements from cosmic microwave background(CMB)anisotropies using the ΛCDM model.We also propose a model-independent method for reconstructing the comoving angular diameter distance D_(M)(z) from the distance modulus μ,using SNe Ia data and combining this result with DESI BAO data of D_(M)/r_(d) to constrain the value of r_(d).We find that the value of r_(d),derived from this model-independent method,is smaller than that obtained from CMB measurements,with a significant discrepancy of at least 4.17σ.All the conclusions drawn in this paper are independent of cosmological models and gravitational theories.展开更多
In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a ser...In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a series of cosmological predictions can be derived solely from two constants, namely the Planck length and the speed of gravity. The speed of gravity can be easily determined without knowledge of the speed of light [1] [2]. This provides a new perspective on cosmology and demonstrates that there is a link between the Planck scale and cosmology. This is fully consistent with a recent quantization of general relativity theory that links general relativity to the Compton frequency and the Planck scale. We examine both the Friedmann cosmology and the recently introduced cosmology based on the extremal solution of the Reissner-Nordström, Kerr, and Kerr-Newman metric.1.展开更多
基金supported in part by the National Key Research and Development Program of China (Grant No.2020YFC2201504)the National Natural Science Foundation of China (Grant Nos.12588101 and 12535002)。
文摘We investigate the null tests of cosmic accelerated expansion by using the baryon acoustic oscillation(BAO)data measured by the dark energy spectroscopic instrument(DESI)and reconstruct the dimensionless Hubble parameter E(z)from the DESI BAO Alcock-Paczynski(AP)data using Gaussian process to perform the null test.We find strong evidence of accelerated expansion from the DESI BAO AP data.By reconstructing the deceleration parameter q(z) from the DESI BAO AP data,we find that accelerated expansion persisted until z■0.7 with a 99.7%confidence level.Additionally,to provide insights into the Hubble tension problem,we propose combining the reconstructed E(z) with D_(H)/r_(d) data to derive a model-independent result r_(d)h=99.8±3.1 Mpc.This result is consistent with measurements from cosmic microwave background(CMB)anisotropies using the ΛCDM model.We also propose a model-independent method for reconstructing the comoving angular diameter distance D_(M)(z) from the distance modulus μ,using SNe Ia data and combining this result with DESI BAO data of D_(M)/r_(d) to constrain the value of r_(d).We find that the value of r_(d),derived from this model-independent method,is smaller than that obtained from CMB measurements,with a significant discrepancy of at least 4.17σ.All the conclusions drawn in this paper are independent of cosmological models and gravitational theories.
文摘In this paper, we will demonstrate that there is a link between cosmology and the Planck scale. It has, in recent years, been shown that the Planck length can be determined independently of G, ℏ, and c, and that a series of cosmological predictions can be derived solely from two constants, namely the Planck length and the speed of gravity. The speed of gravity can be easily determined without knowledge of the speed of light [1] [2]. This provides a new perspective on cosmology and demonstrates that there is a link between the Planck scale and cosmology. This is fully consistent with a recent quantization of general relativity theory that links general relativity to the Compton frequency and the Planck scale. We examine both the Friedmann cosmology and the recently introduced cosmology based on the extremal solution of the Reissner-Nordström, Kerr, and Kerr-Newman metric.1.
