Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
3,308
result(s) for
"Ge, Hui"
Sort by:
Islands and Page curves in charged dilaton black holes
We study the Page curve for eternal Garfinkle–Horowitz–Strominger dilaton black holes in four dimensional asymptotically flat spacetime by using the island paradigm. The results demonstrate that without the island, the entanglement entropy of Hawking radiation is proportional to time and becomes divergent at late times. While taking account of the existence of the island outside the event horizon, the entanglement entropy stops growing at late times and eventually reaches a saturation value. This value is twice of the Bekenstein–Hawking entropy and consistent with the finiteness of the von Neumann entropy of eternal black holes. Moreover, we discuss the impact of the stringy coefficient n and charge Q on the Page time and the scrambling time respectively. For the non-extremal case, the influence of the coefficient n on them is small compared to the influence of the charge Q. However, for the extremal case, the Page time and the scrambling time become divergent or near vanishing. This implies the island paradigm needs further investigation.
Journal Article
الصين فى عشر كلمات
يسلط الكاتب أضواء كاشفة على تعاظم سرعة \"المعجزة الاقتصادية\" في الصين، ويبدو أن كل شي تغير في مثل لمح البصر، وكان ذلك على غرار القفز الطويل حيث جعل الصينيين يقفزون من عصر العوز المادي إلي عصر البذخ والتبذير، ومن عصر السياسة في المقام الأول إلى عصر المال أولا، ومن عصر غريزة القمع إلي عصر الاندفاع والتهور والانغماس في اللهو والمجون، لقد انقضي ثلاثون عاما وأكثر كأنها قفزة في الهواء. وكأن كاتبنا، الذي عاش في كنف التغيرات الهائلة والتحولات الكبري التي اجتاحت الصين في نصف القرن الأخير كان كالسمكة التي تسكن بحورا عميقة تروح وتجئ وسط الغموض تغزل طريقها بين سيقان أعشاب ضخمة فوق أماكن تضوي فيها أشعة الشمس، وتغوص إلى أسفل وأسفل حتى تصل إلي ظلام بارد عميق غامض، وفجأة تنطلق إلى السطح وتلهو فوق الأمواج التي تداعبها الريح، يمسك كاتبنا مبضعه الأدبي-النفسي، ويوضح نقطة سيكولوجية مهمة كأنه الطبيب النفسي الذي يشرح داخل وأعماق النفس الإنسانية، ويقول : إن عصر الكبت المتطرف بعد أن شهد التغيرات الاجتماعية الهائلة من المحتوم أن ينبثق منه عصر آخر مغاير تماما من التسامح المتطرف، وذلك يشبه اللعب على الأرجوحة حيث عندما ينخفض أحد طرفيها، فمن المؤكد أن يعلو كثيرا الطرف الآخر المتأرجح. ولا ينفك يحذر من مغبة أن الحياة الاجتماعية غير المتوازنة من المؤكد أن تجلب الأحلام غير المتوازنة التي بدروها تفرز أحلام التطرف والسعي وراء النجاحات السريعة والقفز فوق المراحل.
Book
Causality of black holes in 4-dimensional Einstein–Gauss–Bonnet–Maxwell theory
We study charged black hole solutions in 4-dimensional (4D) Einstein–Gauss–Bonnet–Maxwell theory to the linearized perturbation level. We first compute the shear viscosity to entropy density ratio. We then demonstrate how bulk causal structure analysis imposes an upper bound on the Gauss–Bonnet coupling constant in the AdS space. Causality constrains the value of Gauss–Bonnet coupling constant
α
GB
to be bounded by
α
GB
≤
0
as
D
→
4
.
Journal Article
Pole-skipping and hydrodynamic analysis in Lifshitz, AdS2 and Rindler geometries
A
bstract
The “pole-skipping” phenomenon reflects that the retarded Green’s function is not unique at a pole-skipping point in momentum space (
ω, k
). We explore the universality of pole-skipping in different geometries. In holography, near horizon analysis of the bulk equation of motion is a more straightforward way to derive a pole-skipping point. We use this method in Lifshitz, AdS
2
and Rindler geometries. We also study the complex hydrodynamic analyses and find that the dispersion relations in terms of dimensionless variables
ω
2
πT
and
k
2
πT
pass through pole-skipping points
ω
n
2
πT
k
n
2
πT
at small
ω
and
k
in the Lifshitz background. We verify that the position of the pole-skipping points does not depend on the standard quantization or alternative quantization of the boundary theory in AdS
2
×
ℝ
d−
1
geometry. In the Rindler geometry, we cannot find the corresponding Green’s function to calculate pole-skipping points because it is difficult to impose the boundary condition. However, we can still obtain “special points” near the horizon where bulk equations of motion have two incoming solutions. These “special points” correspond to the nonuniqueness of the Green’s function in physical meaning from the perspective of holography.
Journal Article
Host selection shapes crop microbiome assembly and network complexity
• Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known.
• Here we examined bacterial communities across 684 samples from soils (rhizosphere and bulk soil) and multiple compartment niches (rhizoplane, root endosphere, phylloplane, and leaf endosphere) in maize (Zea mays)-wheat (Triticum aestivum)/barley (Hordeum vulgare) rotation system under different fertilization practices at two contrasting sites.
• Our results demonstrate that microbiome assembly along the soil-plant continuum is shaped predominantly by compartment niche and host species rather than by site or fertilization practice. From soils to epiphytes to endophytes, host selection pressure sequentially increased and bacterial diversity and network complexity consequently reduced, with the strongest host effect in leaf endosphere. Source tracking indicates that crop microbiome is mainly derived from soils and gradually enriched and filtered at different plant compartment niches. Moreover, crop microbiomes were dominated by a few dominant taxa (c. 0.5% of bacterial phylotypes), with bacilli identified as the important biomarker taxa for wheat and barley and Methylobacteriaceae for maize.
• Our work provides comprehensive empirical evidence on host selection, potential sources and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.
Journal Article
Analogue of the pole-skipping phenomenon in acoustic black holes
The pole-skipping phenomenon is a special property of the retarded Green’s function of black hole perturbations. We turn to its analog in acoustic black holes, which may relate to experiments. The frequencies of these special points are located at negative integer (imaginary) Matsubara frequencies ω=-i2πTn, which are consistent with the imaginary frequencies of quasinormal modes (QNMs). This implies that the lower-half plane pole-skipping phenomena have the same physical meaning as the imaginary part of QNMs, which represents the dissipation of perturbation of acoustic black holes and is related to the instability time scale of perturbation.
Journal Article
Targeting pericyte–endothelial cell crosstalk by circular RNA-cPWWP2A inhibition aggravates diabetes-induced microvascular dysfunction
The crosstalk between vascular pericytes and endothelial cells (ECs) is critical for microvascular stabilization and remodeling; however, the crosstalk is often disrupted by diabetes, leading to severe and even lethal vascular damage. Circular RNAs are a class of endogenous RNAs that regulate several important physiological and pathological processes. Here we show that diabetes-related stress up-regulates cPWWP2A expression in pericytes but not in ECs. In vitro studies show that cPWWP2A directly regulates pericyte biology but indirectly regulates EC biology via exosomes carrying cPWWP2A. cPWWP2A acts as an endogenous miR-579 sponge to sequester and inhibit miR-579 activity, leading to increased expression of angiopoietin 1, occludin, and SIRT1. In vivo studies show that cPWWP2A overexpression or miR-579 inhibition alleviates diabetes mellitus-induced retinal vascular dysfunction. By contrast, inhibition of cPWWP2A-mediated signaling by silencing cPWWP2A or over-expressing miR-579 aggravates retinal vascular dysfunction. Collectively, this study unveils a mechanism by which pericytes and ECs communicate. Intervention of cPWWP2A or miR-579 expression may offer opportunities for treating diabetic microvascular complications.
Journal Article
Thermo-electric transport of dyonic Gubser-Rocha black holes
A
bstract
We study the thermo-electric transport coefficients of an extended version of the Gubser-Rocha model. After reviewing the two relaxation time model from holography and studying the effect of the magnetic field on thermo-electric transports from hydrodynamic theory, we present a new dilatonic dyonic asymptotically AdS black hole solution. Notice that S-duality plays an important role in finding the analytic solution with the magnetic field. Using the AdS/CMT dictionary, we analyze the electric and thermo-electric transport properties of the dual field theory. The resistivity and the Hall angle are both linear in
T
for fixed
k/μ
and
B/μ
2
for low temperatures. For fixed
k/T
and
μ/T
, the electric transport coefficients are strange metallic. The magnetoresistance is approximately quadratic in
B
for various choices of parametrizations. The Nernst signal is a bell-shaped function in terms of the magnetic field even when the momentum relaxation is strong.
Journal Article
Dynamic root microbiome sustains soybean productivity under unbalanced fertilization
Root-associated microbiomes contribute to plant growth and health, and are dynamically affected by plant development and changes in the soil environment. However, how different fertilizer regimes affect quantitative changes in microbial assembly to effect plant growth remains obscure. Here, we explore the temporal dynamics of the root-associated bacteria of soybean using quantitative microbiome profiling (QMP) to examine its response to unbalanced fertilizer treatments (i.e., lacking either N, P or K) and its role in sustaining plant growth after four decades of unbalanced fertilization. We show that the root-associated bacteria exhibit strong succession during plant development, and bacterial loads largely increase at later stages, particularly for Bacteroidetes. Unbalanced fertilization has a significant effect on the assembly of the soybean rhizosphere bacteria, and in the absence of N fertilizer the bacterial community diverges from that of fertilized plants, while lacking P fertilizer impedes the total load and turnover of rhizosphere bacteria. Importantly, a SynCom derived from the low-nitrogen-enriched cluster is capable of stimulating plant growth, corresponding with the stabilized soybean productivity in the absence of N fertilizer. These findings provide new insights in the quantitative dynamics of the root-associated microbiome and highlight a key ecological cluster with prospects for sustainable agricultural management.
Root-associated microbiomes contribute to plant growth and health. Here, the authors unveil the quantitative development of the root microbiome under unbalanced fertilization and highlight a key microbial cluster for soybean productivity.
Journal Article