Yungui Gong
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Research Interests
Yungui Gong has a total of 202 co-authors. Here are the top co-authors by number of shared publications:
- Qing Gao
Southwest University
51 shared publications - Zhu Yi
Faculty of Arts and Sciences, Beijing Normal University, Zhuhai 519087, China
36 shared publications - Bin Wang
Center for Gravitation and Cosmology College of Physical Science and Technology Yangzhou University 225009 Yangzhou China
32 shared publications - Chao Zhang
Ningbo University
31 shared publications - Anzhong Wang
Baylor University
23 shared publications - Zong-Hong Zhu
Beijing Normal University
18 shared publications
Latest Publications
- 13 July 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 53
Observational and thermodynamic aspects of one-dimensional dark energy EoS parametrization models
- 13 July 2026
- Published by Elsevier in Physics of the Dark Universe
- Vol. 53
Observational and thermodynamic aspects of one-dimensional dark energy EoS parametrization models
- Open Access
- 25 June 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (6)
Signatures of the Israel junction II: double photon rings in slowly rotating Kerr spacetime with thin shell
Applying the junction conditions to the slowly rotating Kerr spacetime with a thin shell, when higher order terms in the spin parameter a can be neglected, we find that while the angular momentum L and Carter constant C of the ray remain unchanged upon crossing the shell, its energy E does not. Consequently, the impact parameters $$\eta =L/E$$ and $$\xi =C/E^2$$ of the ray are discontinued at the shell. Utilizing this transformation, we study the shadow of this spacetime and the corresponding images from an equatorial thin accretion disk. The presence of the shell gives rise to distinctive features in the observed images. Notably, we observe distinct double photon rings in the images, which can gradually merge into a single ring. Moreover, the shadow boundaries and the photon rings do not exhibit a one-to-one correspondence. The abrupt changes in redshift factor and the truncated photon regions profoundly influence the image, producing distinctive features such as the step-like structures. These features in shell-equipped spacetimes can help evaluate, through future astronomical observations, the applicability of the Israel junction condition and the shell model in real astrophysical systems.- 25 June 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (6)
Open AccessSignatures of the Israel junction II: double photon rings in slowly rotating Kerr spacetime with thin shell
Applying the junction conditions to the slowly rotating Kerr spacetime with a thin shell, when higher order terms in the spin parameter a can be neglected, we find that while the angular momentum L and Carter constant C of the ray remain unchanged upon crossing the shell, its energy E does not. Consequently, the impact parameters $$\eta =L/E$$ and $$\xi =C/E^2$$ of the ray are discontinued at the shell. Utilizing this transformation, we study the shadow of this spacetime and the corresponding images from an equatorial thin accretion disk. The presence of the shell gives rise to distinctive features in the observed images. Notably, we observe distinct double photon rings in the images, which can gradually merge into a single ring. Moreover, the shadow boundaries and the photon rings do not exhibit a one-to-one correspondence. The abrupt changes in redshift factor and the truncated photon regions profoundly influence the image, producing distinctive features such as the step-like structures. These features in shell-equipped spacetimes can help evaluate, through future astronomical observations, the applicability of the Israel junction condition and the shell model in real astrophysical systems. - Open Access
- 22 June 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (6)
Rescattering of non-minimal coupling scalar particles during inflation
We investigate the rescattering effects arising from non-minimally coupled scalar particles $$\chi $$ that are suddenly produced during inflation. The coupling term $$\xi R \chi ^2$$ significantly enhances resonant particle production compared to minimal coupling scenarios. Consequently, the produced $$\chi $$ particles rescatter off the homogeneous inflaton condensate $$\phi $$ , generating abundant $$\delta \phi $$ quanta within very short time intervals. This process leads to characteristic enhancements in the power spectrum of primordial curvature perturbations at scales corresponding to the moments of particle production. When this occurs at small scales, the power spectrum amplitude can reach as high as $$\mathcal {O}(10^{-2})$$ . Furthermore, analysis of the equilateral bispectrum shows that this mechanism also induces substantial non-Gaussian features.- 22 June 2026
- Published by Springer Nature in The European Physical Journal C
- Vol. 86 (6)
Open AccessRescattering of non-minimal coupling scalar particles during inflation
We investigate the rescattering effects arising from non-minimally coupled scalar particles $$\chi $$ that are suddenly produced during inflation. The coupling term $$\xi R \chi ^2$$ significantly enhances resonant particle production compared to minimal coupling scenarios. Consequently, the produced $$\chi $$ particles rescatter off the homogeneous inflaton condensate $$\phi $$ , generating abundant $$\delta \phi $$ quanta within very short time intervals. This process leads to characteristic enhancements in the power spectrum of primordial curvature perturbations at scales corresponding to the moments of particle production. When this occurs at small scales, the power spectrum amplitude can reach as high as $$\mathcal {O}(10^{-2})$$ . Furthermore, analysis of the equilateral bispectrum shows that this mechanism also induces substantial non-Gaussian features. - 15 April 2026
- Published by IOP Publishing in Chinese Physics Letters
- Vol. 43 (5)
O k null test with multi-task Gaussian processes: cosmic curvature and data compatibility
The O k null test can not only assess whether the cosmic curvature is zero, therefore if true reducing degeneracies between cosmic curvature and other cosmological parameters, but also provide a model-independent check of compatibility between different data sets. However, traditional implementations often require absolute distance data from Type Ia supernovae (SNe Ia) or baryon acoustic oscillation (BAO) measurements, limiting their applicability because such absolute distance data usually are not accessible. The BAO Alcock Paczynski (AP) parameter F AP is a measurement of a distance ratio, making the Dark Energy Spectroscopic Instrument (DESI) AP measurements particularly well suited for the O k null test because no absolute distance measurements are required. We propose a novel null test of cosmic curvature tailored to DESI BAO data that combines F AP with ratios such as D V ′ / D V or DM ′ / D M . Crucially, this construction eliminates the need for absolute distance measurements. We further develop multi-task Gaussian processes to perform the null test. This approach can also be applied to a joint DESI BAO and SNe Ia dataset, and we find that DESI BAO and SNe Ia data are compatible. Although there is ~ 2 σ evidence of nonzero curvature at low redshift z ≲ 0.5, this result is not conclusive largely due to the lack of observational data in the corresponding redshift range.
- 15 April 2026
- Published by IOP Publishing in Chinese Physics Letters
- Vol. 43 (5)
O k null test with multi-task Gaussian processes: cosmic curvature and data compatibility
The O k null test can not only assess whether the cosmic curvature is zero, therefore if true reducing degeneracies between cosmic curvature and other cosmological parameters, but also provide a model-independent check of compatibility between different data sets. However, traditional implementations often require absolute distance data from Type Ia supernovae (SNe Ia) or baryon acoustic oscillation (BAO) measurements, limiting their applicability because such absolute distance data usually are not accessible. The BAO Alcock Paczynski (AP) parameter F AP is a measurement of a distance ratio, making the Dark Energy Spectroscopic Instrument (DESI) AP measurements particularly well suited for the O k null test because no absolute distance measurements are required. We propose a novel null test of cosmic curvature tailored to DESI BAO data that combines F AP with ratios such as D V ′ / D V or DM ′ / D M . Crucially, this construction eliminates the need for absolute distance measurements. We further develop multi-task Gaussian processes to perform the null test. This approach can also be applied to a joint DESI BAO and SNe Ia dataset, and we find that DESI BAO and SNe Ia data are compatible. Although there is ~ 2 σ evidence of nonzero curvature at low redshift z ≲ 0.5, this result is not conclusive largely due to the lack of observational data in the corresponding redshift range.
- Open Access
Dark matter distributions around extreme mass ratio inspirals: effects of radial pressure and relativistic treatment
We investigate different treatments of dark matter (DM) distributions surrounding extreme mass ratio inspirals (EMRIs) to assess their impact on orbital evolution and gravitational wave emission. Density profiles derived from the mass current and from the energy-momentum tensor using a distribution function yield consistent results, but both differ substantially from profiles obtained using an anisotropic fluid model based on Einstein cluster ansatz. We find that the inclusion of radial pressure significantly modifies both the orbital dynamics and the resulting gravitational wave waveforms. By analyzing waveform dephasing and mismatches, we show that a fully relativistic treatment of DM distributions can substantially alter the detectability thresholds of DM halos. Our results demonstrate that radial pressure and relativistic modeling of DM are essential for accurately describing the dynamics and observational signatures of EMRIs embedded in DM halos.
Open AccessDark matter distributions around extreme mass ratio inspirals: effects of radial pressure and relativistic treatment
We investigate different treatments of dark matter (DM) distributions surrounding extreme mass ratio inspirals (EMRIs) to assess their impact on orbital evolution and gravitational wave emission. Density profiles derived from the mass current and from the energy-momentum tensor using a distribution function yield consistent results, but both differ substantially from profiles obtained using an anisotropic fluid model based on Einstein cluster ansatz. We find that the inclusion of radial pressure significantly modifies both the orbital dynamics and the resulting gravitational wave waveforms. By analyzing waveform dephasing and mismatches, we show that a fully relativistic treatment of DM distributions can substantially alter the detectability thresholds of DM halos. Our results demonstrate that radial pressure and relativistic modeling of DM are essential for accurately describing the dynamics and observational signatures of EMRIs embedded in DM halos.
- Open Access
Signatures of the Israel Junction II: Double Photon Rings in Slowly Rotating Kerr Spacetime with Thin Shell
Applying the junction conditions to the slowly rotating Kerr spacetime with a thin shell, we find that while the angular momentum $L$ and Carter constant $C$ of the ray remain unchanged upon crossing the shell, its energy $E$ does not. Consequently, the impact parameters $η=L/E$ and $ξ=C/E^2$ of the ray are discontinued at the shell. Utilizing this transformation, we study the shadow of this spacetime and the corresponding images from an equatorial thin accretion disk. The presence of the shell gives rise to distinctive features in the observed images. Notably, we observe distinct double photon rings in the images, which can gradually merge into a single ring. Moreover, the shadow boundaries and the photon rings do not exhibit a one-to-one correspondence. The abrupt changes in redshift factor and the truncated photon regions profoundly influence the image, producing distinctive features such as the step-like structures. These features in shell-equipped spacetimes can help evaluate, through future astronomical observations, the applicability of the Israel junction condition and the shell model in real astrophysical systems.Open AccessSignatures of the Israel Junction II: Double Photon Rings in Slowly Rotating Kerr Spacetime with Thin Shell
Applying the junction conditions to the slowly rotating Kerr spacetime with a thin shell, we find that while the angular momentum $L$ and Carter constant $C$ of the ray remain unchanged upon crossing the shell, its energy $E$ does not. Consequently, the impact parameters $η=L/E$ and $ξ=C/E^2$ of the ray are discontinued at the shell. Utilizing this transformation, we study the shadow of this spacetime and the corresponding images from an equatorial thin accretion disk. The presence of the shell gives rise to distinctive features in the observed images. Notably, we observe distinct double photon rings in the images, which can gradually merge into a single ring. Moreover, the shadow boundaries and the photon rings do not exhibit a one-to-one correspondence. The abrupt changes in redshift factor and the truncated photon regions profoundly influence the image, producing distinctive features such as the step-like structures. These features in shell-equipped spacetimes can help evaluate, through future astronomical observations, the applicability of the Israel junction condition and the shell model in real astrophysical systems. - 31 December 2025
- Published by Elsevier in Physics of the Dark Universe
- Vol. 51
Images and photon regions of continuous photon sphere spacetime
- 31 December 2025
- Published by Elsevier in Physics of the Dark Universe
- Vol. 51
Images and photon regions of continuous photon sphere spacetime
- 24 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Generic effective sources for first-order in mass-ratio gravitational self-force calculations in Schwarzschild spacetime
- 24 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Generic effective sources for first-order in mass-ratio gravitational self-force calculations in Schwarzschild spacetime
- 17 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Primordial black hole formation and spin in matter domination revisited
- 17 November 2025
- Published by American Physical Society (APS) in Physical Review D
- Vol. 112 (10)
Primordial black hole formation and spin in matter domination revisited
- 12 November 2025
- Published by Springer Nature in Science China Physics, Mechanics & Astronomy
- Vol. 69 (1) , 210401
Gravitational wave cosmology
- 12 November 2025
- Published by Springer Nature in Science China Physics, Mechanics & Astronomy
- Vol. 69 (1) , 210401
Gravitational wave cosmology