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En-Wei Liang

Publications and source records attributed to En-Wei Liang.

At least 109 records · Page 6Linked to original sources
arXiv2023

Optical appearance of a thin-shell wormhole with a Hayward profile

The optical properties of a thin-shell wormhole (TSW) with a Hayward profile is investigated. Adopting the ray-tracing method, we demonstrate that the TSW's contralateral spacetime is capable of reflecting a significant portion of light back to the observer spacetime. We analyze the effective potential, light deflection, and azimuthal angle of the TSW and find that these quantities are affected by the mass ratio of the black holes (BHs). Specifically, if the mass of the contralateral spacetime BH is greater than that of the original spacetime BH, and the impact parameter satisfies the condition $Hb_{\rm c2}<b_{1}<b_{\rm c1}$, the trajectory of the photon exhibits round-trip characteristics. Assuming the presence of a thin accretion disk surrounding the observing spacetime BH, our results indicate that the image formed by the TSW exhibits additional photon rings and a lensing band compared to an image produced by a BH alone.

gr-qc↗
arXiv2023

Event Rate of Fast Radio Burst from Binary Neutron-star Mergers

It is proposed that one-off fast radio burst (FRB) with periodic structures may be produced during the inspiral phase of a binary neutron-star (BNS) merger. In this paper, we study the event rate of such kind of FRB. We first investigate the properties of two one-off FRBs with periodic structures (i.e., FRB~20191221A and FRB~20210213A) in this scenario, by assuming the fast magnetosonic wave is responsible for their radio emission. For the luminosities and periods of these bursts, it is found that the pre-merger BNS with magnetic field strength $B\gtrsim 10^{12}\,{\rm Gs}$ is required. This is relatively high compared with that of the most of the BNSs observed in our Galaxy, of which the magnetic field is around $10^{9}\,{\rm Gs}$. Since the observed BNSs in our Galaxy are the binaries without suffering merger, a credited event rate of BNS-merger originated FRBs should be estimated by considering the evolution of both the BNS systems and their magnetic fields. Based on the population synthesis and adopting a decaying magnetic field of NSs, we estimate the event rate of BNS-mergers relative to their final magnetic fields. We find that the rapid merged BNSs tend to merge with high magnetization, and the event rate of BNS-merger originated FRBs, i.e., the BNS-mergers with both NSs' magnetic field being higher than $10^{12}\,{\rm Gs}$ is $\sim8\times10^{4}\,\rm{yr}^{-1}$ ($19 \%$ of the total BNS-mergers) in redshift $z<1$.

astro-ph.HE↗
arXiv2023

Detection of Quasi-periodic Oscillations in SGR 150228213

The detection of quasi-periodic oscillations (QPOs) in magnetar giant flares (GFs) has brought a new perspective to study the mechanism of magnetar bursts. Due to the scarcity of GFs, searching QPOs from magnetar short bursts is reasonable. Here we report the detection of a high frequency QPO at approximately 110 Hz and a wide QPO at approximately 60 Hz in a short magnetar burst SGR 150228213, with a confidence level of 3.35$σ$. This burst was initially attributed to 4U 0142+61 by $Fermi$/GBM on location, but we haven't detected such QPOs in other bursts from this magnetar. We also found that there was a repeating fast radio burst associated with SGR 150228213 on location. Finally, we discuss the possible origins of SGR 150228213.

astro-ph.HE↗
arXiv2023

Comparison of Burst Properties between FRB 20190520B and FRB 20121102A

A comparative analysis of the individual bursts between FRB 20190520B and FRB 20121102A is presented by compiling a sample of bursts in multiple wavelengths. It is found that the peak frequency ($ν_p$) distribution of the bursts of FRB 20190520B illustrates four discrete peaks in $\sim1-6$ GHz and their spectral width distribution can be fitted with a log-normal function peaking at 0.35 GHz. The discrete $ν_p$ distribution and the narrow-banded spectral feature are analogous to FRB 20121102A. The burst duration of FRB 20190520B in the rest frame averages 10.72 ms, longer than that of FRB 20121102A by a factor 3. The specific energy ($E_{\rm μ_{\rm c}}$) at 1.25 GHz of FRB 20190520B observed with the FAST telescope narrowly ranges in $[0.4, 1]\times 10^{38}$ erg, different from the bimodal $E_{\rm μ_{\rm c}}$ distribution of FRB 20121102A. Assuming a Gaussian spectral profile of the bursts, our Monte Carlo simulation analysis suggests that a power-law (PL) or a cutoff power-law (CPL) energy function can comparably reproduce the $E_{\rm μ_{\rm c}}$ distribution of FRB 20190520B. The derived energy function index of the PL model is $4.46\pm 0.17$, much steeper than that of FRB 20121102A ($1.82^{+0.10}_{-0.30}$). For the CPL model, we obtain an index of $0.47$ and a cutoff energy of $7.4\times 10^{37}$ erg. Regarding the predicted $ν_p$ distribution in 1-2 GHz, the CPL model is more preferred than the PL model. These results indicate that FRB 20190520B and FRB 20121102A shares similar spectral properties, but their energy functions are intrinsically different.

astro-ph.HE↗
arXiv2023

Confining Burst Energy Function and Spectral Fringe Pattern of FRB 20121102A with Multifrequency Observations

The observed spectral shapes variation and tentative bimodal burst energy distribution (E-distribution) of fast radio burst (FRB) 20121102A with the FAST telescope are great puzzles. Adopting the published multifrequency data observed with the FAST and Arecibo telescopes at $L$ band and the GBT telescope at $C$ band, we investigate these puzzles through Monte Carlo simulations. The intrinsic energy function (E-function) is modeled as $dp/dE\propto E^{-α_{\rm E}}$, and the spectral profile is described as a Gaussian function. A fringe pattern of its spectral peak frequency ($ν_{\rm p}$) in 0.5-8 GHz is inferred from the $ν_{\rm p}$ distribution of the GBT sample. We estimate the likelihood of $α_{\rm E}$ and the standard deviation of the spectral profile ($σ_{\rm s}$) by utilizing the Kolmogorov--Smirnov (K-S) test probability for the observed and simulated specific E-distributions. Our simulations yields $α_{\rm E}=1.82^{+0.10}_{-0.30}$ and $σ_{\rm s}=0.18^{+0.28}_{-0.06}$ ($3σ$ confidence level) with the FAST sample. These results suggest that a single power-law function is adequate to model the E-function of FRB 20121102A. The variations of its observed spectral indices and E-distributions with telescopes in different frequency ranges are due to both physical and observational reasons, i.e. narrow spectral width for a single burst and discrete $ν_{p}$ fringe pattern in a broad frequency range among bursts, and the selection effects of the telescope bandpass and sensitivity. The putative $ν_{p}$ fringe pattern cannot be explained with the current radiation physics models of FRBs. Some caveats of possible artificial effects that may introduce such a feature are discussed.

astro-ph.HE↗
arXiv2023

Very-High-Energy Gamma-Ray Afterglows of GRB 201015A and GRB 201216C

Gamma-ray bursts (GRBs) 201015A and 201216C are valuable cases with detection of very high energy (VHE) gamma-ray afterglows. By analysing their prompt emission data, we find that GRB 201216C is an extremely energetic long GRB with a hard gamma-ray spectrum, while GRB 201015A is a relative sub-energetic, soft spectrum GRB. Attributing their radio-optical-X-ray afterglows to the synchrotron radiation of the relativistic electrons accelerated in their jets, we fit their afterglow lightcurves with the standard external shock model and infer their VHE afterglows from the synchrotron self-Compton scattering process of the electrons. It is found that the jet of GRB 201015A is mid-relativistic ($Γ_0=44$) surrounded by a very dense medium ($n=1202$ cm$^{-3}$) and the jet of GRB 201216C is ultra-relativistic ($Γ_0=331$) surrounded by a moderate dense medium ($n=5$ cm$^{-3}$). The inferred peak luminosity of the VHE gamma-ray afterglows of GRB 201216C is approximately $10^{-9}$ erg cm$^{-2}$ s$^{-1}$ at $57-600$ seconds after the GRB trigger, making it can be detectable with the MAGIC telescopes at a high confidence level, even the GRB is at a redshift of 1.1. Comparing their intrinsic VHE gamma-ray lightcurves and spectral energy distributions with GRBs~180720B, 190114C, and 190829A, we show that their intrinsic peak luminosity of VHE gamma-ray afterglows at $10^{4}$ seconds post the GRB trigger is variable from $10^{45}$ to $5\times 10^{48}$ erg s$^{-1}$, and their kinetic energy, initial Lorentz factor, and medium density are diverse among bursts.

astro-ph.HE↗
arXiv2023

Hard TeV Gamma-Ray Afterglows of Nearby GRB 190829A as a Tentative Signature of Ultra-High-Energy Cosmic Rays Accelerated in Gamma-Ray Burst Jets

The observed hard TeV gamma-ray spectrum of the nearby gamma-ray burst (GRB) 190829A may challenge the conventional leptonic GRB afterglow model. It has been proposed that an ultra-high-energy (UHE; $\varepsilon^{'}_{\rm p}\sim 10^{20}$ eV) proton population can be pre-accelerated by internal shocks in GRB jets. We study possible signatures of the UHE protons embedded in the TeV afterglows when they escape the afterglow fireball. We show that the leptonic model can represent the observed multiwavelength lightcurves and spectral energy distributions of GRB 190829A by considering the uncertainties of the model parameters. Attributing the TeV gamma-ray afterglows to the emission of both the electron self-Compton scattering process and the UHE proton synchrotron radiations in the afterglow fireball, we obtain tentative upper limits of $\log_{10} \varepsilon_{\rm p}^{\prime}/{\rm eV}\sim 20.46$ and $\log_{10}E_{\rm p, total}/{\rm erg}\leq 50.75$, where $E_{\rm p, total}$ is the total energy of the proton population. The synchrotron radiations of the UHE protons should dominate the early TeV gamma-ray afterglows, implying that early observations are critical for revealing the UHE proton population.

astro-ph.HE↗
arXiv2023

A huge-amplitude white-light superflare on a L0 brown dwarf discovered by GWAC survey

White-light superflares from ultra cool stars are thought to be resulted from magnetic reconnection, but the magnetic dynamics in a fully convective star is not clear yet. In this paper, we report a stellar superflare detected with the Ground Wide Angle Camera (GWAC), along with rapid follow-ups with the F60A, Xinglong 2.16m and LCOGT telescopes. The effective temperature of the counterpart is estimated to be $2200\pm50$K by the BT-Settl model, corresponding to a spectral type of L0. The $R-$band light curve can be modeled as a sum of three exponential decay components, where the impulsive component contributes a fraction of 23\% of the total energy, while the gradual and the shallower decay phases emit 42\% and 35\% of the total energy, respectively. The strong and variable Balmer narrow emission lines indicate the large amplitude flare is resulted from magnetic activity. The bolometric energy released is about $6.4\times10^{33}$ ergs, equivalent to an energy release in a duration of 143.7 hours at its quiescent level. The amplitude of $ΔR=-8.6 $mag ( or $ΔV=-11.2$ mag), placing it one of the highest amplitudes of any ultra cool star recorded with excellent temporal resolution. We argue that a stellar flare with such rapidly decaying and huge amplitude at distances greater than 1 kpc may be false positive in searching for counterparts of catastrophic events such as gravitational wave events or gamma-ray bursts, which are valuable in time-domain astronomy and should be given more attention.

astro-ph.SR↗
arXiv2023

Model-Independent Determination of $H_0$ and $Ω_{K,0}$ using Time-Delay Galaxy Lenses and Gamma-Ray Bursts

Combining the `time-delay distance' ($D_{Δt}$) measurements from galaxy lenses and other distance indicators provides model-independent determinations of the Hubble constant ($H_0$) and spatial curvature ($Ω_{K,0}$), only based on the validity of the Friedmann-Lemaître-Robertson-Walker (FLRW) metric and geometrical optics. To take the full merit of combining $D_{Δt}$ measurements in constraining $H_0$, we use gamma-ray burst (GRB) distances to extend the redshift coverage of lensing systems much higher than that of Type Ia Supernovae (SNe Ia) and even higher than quasars, whilst the general cosmography with a curvature component is implemented for the GRB distance parametrizations. Combining Lensing+GRB yields $H_0=71.5^{+4.4}_{-3.0}$~km s$^{-1}$Mpc$^{-1}$ and $Ω_{K,0} = -0.07^{+0.13}_{-0.06}$ (1$σ$). A flat-universe prior gives slightly an improved $H_0 = 70.9^{+4.2}_{-2.9}$~km s$^{-1}$Mpc$^{-1}$. When combining Lensing+GRB+SN Ia, the error bar $ΔH_0$ falls by 25\%, whereas $Ω_{K,0}$ is not improved due to the degeneracy between SN Ia absolute magnitude, $M_B$, and $H_0$ along with the mismatch between the SN Ia and GRB Hubble diagrams at $z\gtrsim 1.4$. Future increment of GRB observations can help to moderately eliminate the $M_B-H_0$ degeneracy in SN Ia distances and ameliorate the restrictions on cosmographic parameters along with $Ω_{K,0}$ when combining Lensing+SN Ia+GRB. We conclude that there is no evidence of significant deviation from a (an) flat (accelerating) universe and $H_0$ is currently determined at 3\% precision. The measurements show great potential to arbitrate the $H_0$ tension between the local distance ladder and cosmic microwave background measurements and provide a relevant consistency test of the FLRW metric.

astro-ph.CO↗
arXiv2023

GRB 200829A: External Shock Origin of the Very Early Prompt Emission?

Long-duration GRB~200829A was detected by Fermi-GBM and Swift-BAT/XRT, and then rapidly observed by other ground-based telescopes. It has a weak $γ$-ray emission in the very early phase and followed by a bright spiky $γ$-ray emission pulse. The radiation spectrum of the very early emission is best fitted by a power-law function with index $\sim -1.7$. However, the bright spiky $γ$-ray pulse, especially the time around the peak, exhibits a distinct two-component radiation spectra, i.e., Band function combined with a blackbody radiation spectrum. We infer the photospheric properties and reveal a medium magnetization at photospheric position by adopting the initial size of the outflow as $r_0=10^9$~cm. It implies that Band component in this pulse may be formed during the dissipation of magnetic field. The power-law radiation spectra found in the very early prompt emission may imply the external-shock origination of this phase. Then, we perform Markov Chain Monte Carlo method fitting on the light-curves of this burst, where the jet corresponding to the $γ$-ray pulses at around $20$~s is used to refresh the external-shock. It is shown that the light-curves of very early phase and X-ray afterglow after $40$~s, involving the X-ray bump at around $100$~s, can be well modelled in the external-shock scenario. For the obtained initial outflow, we estimate the minimum magnetization factor of the jet based on the fact that the photospheric emission of this jet is missed in the very early phase.

astro-ph.HE↗
arXiv2022

Thermal and nonthermal emission from a peculiar long-duration GRB 211211A

Long-duration GRB 211211A that lacks a supernova emission even down to very stringent limits at such a low redshift $z=0.076$ and is associated with kilonova emission, suggests that its physical origin is from a binary compact star merger. By reanalyzing its data observed with the Gamma-Ray Burst Monitor on board the Fermi mission, we find that both time-integrated and time-resolved spectra can be fitted well by using a 2SBPL plus blackbody (2SBPL+BB) model in the prompt emission. The bulk Lorentz factors ($Γ_{\rm ph}$) of the outflow can be inferred by invoking the observed thermal emission at the photosphere radius within a pure fireball model, and we find out that the temporal evolution of $Γ_{\rm ph}$ seems to be tracking with the light curve. The derived values of $Γ_{\rm ph}$ are also consistent with the $Γ_{\rm ph}$-$L_{γ, \rm iso}$/$E_{γ, \rm iso}$ correlations that had been found in other bursts. Moreover, we also calculate the magnetization factor $σ_{0}$ in the central engine and $σ_{\rm ph}$ at the photosphere radius within the framework of a hybrid jet model, and find that the values of both $1+σ_{\rm 0}$ and $1+σ_{\rm ph}$ are larger than 1 for different time slices. It suggests that at least the Poynting-flux component is indeed existent in the outflow. If this is the case, one possible physical interpretation of thermal and nonthermal emissions in GRB 211211A is from the contributions of both $ν\barν$ annihilation and the Blandford-Znajek mechanisms in the relativistic jet when a stellar mass black hole resides in the central engine.

astro-ph.HE↗
arXiv2022

Jets in a Gamma-Ray Burst During its Prompt Emission: Evolution of Lorentz Factor

Knowledge about the Lorentz factor and its evolution of relativistic jets in gamma-ray bursts (GRBs) is crucial to understand their physics. An exact value of bulk Lorentz factor can be estimated based on a high-energy spectral cutoff, which may appear in GRBs' prompt emission owing to the absorption of photon-photon pair production. In this work, we focus on the investigation of the bulk Lorentz factor evolution of jets in an individual burst. Based on \textsl{Fermi} observations, we search for the bursts with multiple $γ$-ray pulses characterized by a high-energy spectral cutoff, and nine GRBs are obtained. Together with the estimation of the pulse duration and radiation spectrum, the Lorentz factor of jets corresponding to different pulses in an individual GRB are estimated. It is shown that the Lorentz factor of jets in an individual GRB fluctuates within a certain range and without a general trend in these nine GRBs. In addition, the Lorentz factors of the jets in GRBs~130821A, 160509A and 160625B seem to increase with time. We also study the relations among $L_{\rm iso }$, $E_{\rm p,z}$, and $Γ$ for the pulses in our sample, which is found to be consistent with that found in previous works.

astro-ph.HE↗
arXiv2022

Photometric and Spectroscopic Observations of GRB 210104A: Bright Reverse shock Emission and Dense Circumburst Environment

Early afterglow observations of gamma-ray bursts (GRBs) are valuable for exploring the properties of their jets and ambient medium. We report our photometric and spectroscopic observations of GRB 210104A and discuss its jet properties with multiwavelength data. Our spectroscopic observation reveals several absorption features and a tentative redshift of 0.46 is identified. A bright optical flare that has a peak brightness of $R=13$ mag at $112\pm 7$~s was observed in the $R$ band during $67\sim 165$ seconds post the GRB trigger. The flux of the $R$-band afterglow decays with a slope of $α_{\rm O}={-0.91\pm 0.03}$ at $t>650$~s. The early X-ray afterglow lightcurve is a smooth bump, and it decays with a slope of $α_{\rm X}=-1.18\pm 0.01$ at late epoch. Our joint spectral fit to the optical-X-ray afterglows during $(1.1-1.3)\times 10^{4}$~s yields a photon index $Γ_{\rm O,X}=-1.82\pm 0.04$. The derived host galaxy extinction is $A_{R}=0.87$. Attributing the early optical flare to the reverse-shock (RS) emission and the late optical-X-ray emission to the forward shock emission; the optical and X-ray lightcurves at $t<3\times 10^4$~s can be well fit adopting an Markov Chain Monte Carlo algorithm. Comparing the properties of GRB 210104A with other GRBs that have detection of bright RS emission, we show that its jet is mildly magnetized ($R_{\rm B}=28$), with high radiation efficiency ($77\%$), is sub-energetic ($E_{\rm k, iso}=4.5\times 10^{51}$ erg), and moderately relativistic ($Γ_0\sim 35$) in a density medium ($n_{0}\sim 417\;{\rm cm}^{-3}$). It follows the tight $L_{γ,\rm iso}-E_{\rm p,z}-Γ_{0}$ relation as with typical GRBs.

astro-ph.HE↗
arXiv2022

Magnetic activities and parameters of 43 flare stars in the GWAC archive

In the archive of the Ground Wide Angle Camera (GWAC), we found 43 white light flares from 43 stars, among which, three are sympathetic or homologous flares, and one of them also has a quasi-periodic pulsation with a period of $13.0\pm1.5$ minutes. Among these 43 flare stars, there are 19 new active stars and 41 stars that have available TESS and/or K2 light curves, from which we found 931 stellar flares. We also obtained rotational or orbital periods of 34 GWAC flare stars, of which 33 are less than 5.4 days, and ephemerides of three eclipsing binaries from these light curves. Combining with low resolution spectra from LAMOST and the Xinglong 2.16m telescope, we found that $L_{\rm Hα}/L_{\rm bol}$ are in the saturation region in the rotation-activity diagram. From the LAMOST medium-resolution spectrum, we found that Star \#3 (HAT 178-02667) has double H$α$ emissions which imply it is a binary, and two components are both active stars. Thirteen stars have flare frequency distributions (FFDs) from TESS and/or K2 light curves. These FFDs show that the flares detected by GWAC can occur at a frequency of 0.5 to 9.5 yr$^{-1}$. The impact of flares on habitable planets was also studied based on these FFDs, and flares from some GWAC flare stars may produce enough energetic flares to destroy ozone layers, but none can trigger prebiotic chemistry on their habitable planets.

astro-ph.SR↗
arXiv2022

Diffuse $γ$-ray emission around the massive star forming region of Carina Nebula Complex

We report the Fermi Large Area Telescope (Fermi-LAT) detection of the $γ$-ray emission toward the massive star forming region of Carina Nebula Complex (CNC). Using the latest source catalog and diffuse background models, we found that the GeV $γ$-ray emission in this region can be resolved into three different components. The GeV $γ$-ray emission from the central point source is considered to originate from the Eta Carina ($η$ Car). We further found the diffuse GeV $γ$-ray emission around the CNC which can be modelled by two Gaussian disks with radii of 0.4°(region A) and 0.75°(region B), respectively. The GeV $γ$-ray emission from both the regions A and B have good spatial consistency with the derived molecular gas in projection on the sky. The GeV $γ$-ray emission of region A reveals a characteristic spectral shape of the pion-decay process, which indicates that the $γ$-rays are produced by the interactions of hadronic cosmic rays with ambient gas. The $γ$-rays spectrum of region B has a hard photon index of 2.12 $\pm$ 0.02, which is similar to other young massive star clusters. We argue that the diffuse GeV $γ$-ray emission in region A and region B likely originate from the interaction of accelerated protons in clusters with the ambient gas.

astro-ph.HE↗
arXiv2022

X-ray and GeV-gamma-ray emission property of TeV Compact Symmetric Object PKS 1413+135 and Implication for Episodic Jet Activity

PKS 1413+135, a compact symmetric object (CSO) with a two-side pc-scale structure in its miniature radio morphology, is spatially associated with 4FGL J1416.1+1320 and recently detected with MAGIC telescopes. We comprehensively analyze its X-ray and GeV gamma-ray observation data for revealing its high energy radiation physics. It is found that the source is in a low-flux stage before MJD 58500 and experiences violent outbursts after MJD 58500 in the GeV band. The flux at 10 GeV varies ~3 orders of magnitude, and the GeV-flux variation is accompanied by the clear spectral variation, which is characterized as a soft log-parabola spectrum in the low-flux state and a hard power-law spectrum in the bright flares. The variability amplitude of X-rays is lower than that of gamma-rays, and no correlation of variability between gamma-rays and X-rays is observed. Fitting the broadband spectral energy distribution during a GeV outburst with a multi-zone leptonic model, we show that the GeV gamma-rays are attributed to the external Compton process while the X-rays are hybrid of several components. The predicted TeV gamma-ray flux during the GeV outburst is consistent with the detection of MAGIC telescopes. These results, together with its CSO radio morphology, imply that PKS 1413+135 has the episodic nuclear jet activities. The weak gamma-ray emission before MJD 58500 may be from its sub-pc-/pc-scale jet component powered by previous activities, and the violent outbursts with short-timescale variability after MJD 58500 could be attributed to the recently restarted jet activity.

astro-ph.HE↗
arXiv2022

QED and accretion flow models effect on optical appearance of Euler-Heisenberg black holes

Taking the quantum electrodynamics (QED) effect into account, we investigate the geometrical-optics appearance of the Euler-Heisenberg (EH) black hole (BH) under the different accretion flows context, which depends on the BH space-time structure and different sources of light. The more significant magnetic charge leads to the smaller shadow radius for the EH BH, while the different values of the EH parameter do not ruin it. Different features of the corresponding two-dimensional shadow images are derived for the three optically thin accretion flow models. It is shown that the total observed intensity in the static spherical accretion flow scenario leads than that of the infalling spherical accretion flow under same parameters, but the size and position of the EH BH shadows do not change in both of these accretions flows, implying that the BH shadow size depends on the geometric space-time and the shadows luminosities rely on the accretion flow morphology. Of particular interest is that a thin disk accretion model illuminated the BH, we found that the contribution of the lensing ring to the total observed flux is less than 5\%, and the photon ring is less than 2\%, indicating that the direct emission dominates the optical appearance of the EH BH. It is also believed that the optical appearance of the BH image depends on the accretion disk radiation position in this scenario, which can serve as a probe for the disk structure around the active galactic nucleus (AGN) of M87^{*} like.

gr-qc↗
arXiv2022

High-order QED correction impacts on phase transition of the Euler-Heisenberg AdS black hole

Two-phase transition branches of the Euler-Heisenberg (EH) anti-de Sitter (AdS) black hole (BH) were derived from its phase transition critical behavior by Magos et al. [Phys. Rev. D. 102, 084011 (2020)]. We found that the phase transition is unstable. Considering the high-order quantum electrodynamics (QED) correction, we re-derive the EHAdS BH solution and investigate its critical thermodynamic quantities. It is found that the corrected EHAdS BH has only one stable phase transition branch, and its critical exponents are equivalent to that of the vdW system. From the microscopic point of view, we also derive its normalized scalar curvature based on the Ruppeiner geometry. Different from two concave surfaces of the scalar curvature without considering the high-order QED correction, we show that the corrected Ruppeiner geometry has only one concave surface. Our results indicate that the phase transition instability derived by Magos $et~al.$ is due to without considering the high-order QED correction.

hep-th↗