arXiv subjects

Zhaopeng Wang

Publications and source records attributed to Zhaopeng Wang.

6 recordsLinked to original sources

arXiv2026

A Critical Density Estimate for the Vlasov--Poisson System: Energy Conservation and Moment Propagation

This paper establishes a critical space--time density estimate for the three-dimensional Vlasov--Poisson system in the whole space and on the torus. This estimate has two consequences. First, every nonnegative weak solution with finite initial kinetic energy in the bounded finite-energy weak-solution class conserves the total energy. This gives a positive answer, within this class, to the energy-conservation question raised by Lions and Perthame. Second, in the periodic repulsive case, it yields propagation of every velocity moment of order \(k>2\), thereby closing the previously unresolved interval \(2<k\leq3\).

math.AP↗

arXiv2026

A Coulomb-Corrected Labeled Energy and Growth Estimates for the Vlasov-Poisson System

This paper introduces a Coulomb-corrected labeled energy for smooth compactly supported solutions of the three-dimensional repulsive Vlasov--Poisson system. The resulting identity replaces the direct electric-field term along a characteristic by a weighted singular integral, which can be estimated more effectively. Thus this structure yields improved bounds on the velocity support and the decay of the electric field.

math.AP↗

arXiv2020

Dead Zones of Classical Habitability in Stellar Binary Systems

Although habitability, defined as the general possibility of hosting life, is expected to occur under a broad range of conditions, the standard scenario to allow for habitable environments is often described through habitable zones (HZs). Previous work indicates that stellar binary systems typically possess S-type or P-type HZs, with the S-type HZs forming ring-type structures around the individual stars and P-type HZs forming similar structures around both stars, if considered a pair. However, depending on the stellar and orbital parameters of the system, typically, there are also regions within the systems outside of the HZs, referred to as dead zones (DZs). In this study, we will convey quantitative information on the width and location of DZs for various systems. The results will also depend on the definition of the stellar HZs as those are informed by the planetary climate models.

astro-ph.SR↗

arXiv2019

S-Type and P-Type Habitability in Stellar Binary Systems: A Comprehensive Approach III. Results for Mars, Earth, and super-Earth Planets

In Paper I and II, a comprehensive approach was utilized for the calculation of S-type and P-type habitable regions in stellar binary systems for both circular and elliptical orbits of the binary components. It considered a joint constraint including orbital stability and a habitable region for a possible system planet through the stellar radiative energy fluxes ("radiative habitable zone"; RHZ). Specifically, the stellar S-type and P-type RHZs are calculated based on the solution of a fourth order polynomial. However, in concurrent developments, mostly during 2013 and 2014, important improvements have been made in the computation of stellar habitable zones for single stars based on updated climate models given by R. K. Kopparapu and collaborators. These models entail considerable changes for the inner and outer limits of the stellar habitable zones. Moreover, regarding the habitability limit given by the runaway greenhouse effect, notable disparities were identified between Earth, Mars, and super-Earth planets due to differences in their atmospheric models, thus affecting their potential for habitability. It is the aim of this study to compute S-type and P-type habitable regions of binaries in response to the updated planetary models. Moreover, our study will also consider improved relationships between effective temperatures, radii, and masses for low-luminosity stars.

astro-ph.EP↗

arXiv2017

Fitting Formulae and Constraints for the Existence of S-type and P-type Habitable Zones

We derive fitting formulae for the quick determination of the existence of S-type and P-type habitable zones in binary systems. Based on previous work, we consider the limits of the climatological habitable zone in binary systems (which sensitively depend on the system parameters) based on a joint constraint encompassing planetary orbital stability and a habitable region for a possible system planet. Additionally, we employ updated results on planetary climate models obtained by Kopparapu and collaborators. Our results are applied to four P-type systems (Kepler-34, Kepler-35, Kepler-413, and Kepler-1647) and two S-type systems (TrES-2 and KOI-1257). Our method allows to gauge the existence of climatological habitable zones for these systems in a straightforward manner with detailed consideration of the observational uncertainties. Further applications may include studies of other existing systems as well as systems to be identified through future observational campaigns.

astro-ph.EP↗

arXiv2016

Fitting Formulas for Determining the Existence of S-type and P-type Habitable Zones in Binary Systems: First Results

We present initial work about attaining fitting formulas for the quick determination of the existence of S-type and P-type habitable zones in binary systems. Following previous work, we calculate the limits of the climatological habitable zone in binary systems (which sensitively depend on the system parameters) based on a joint constraint encompassing planetary orbital stability and a habitable region for a possible system planet. We also consider updated results on planetary climate models previously obtained by Kopparapu and collaborators. Fitting equations based on our work are presented for selected cases.

astro-ph.EP↗