8 papers
A Markovian Traffic Equilibrium Model for Ride-Hailing
Song Gao, Hanyu Cheng, Chiwei Yan +1
We develop a Markovian traffic equilibrium model for ride-hailing in which vehicles, whether empty or hired, make sequential order-acceptance and link-choice decisions over a traff…
Beyond Two Parameters: Revisiting Dark Energy with the Latest Cosmic Probes
Hanyu Cheng, Supriya Pan, Eleonora Di Valentino
Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. While such models offer greater flex…
Primordial Black Hole Abundance from Reionization
Ziwen Yin, Hanyu Cheng, Luca Visinelli
We derive robust constraints on the initial abundance of evaporating primordial black holes (PBHs) using the reionization history of the Universe as a cosmological probe. We focus…
Constraining the axiverse with reionization
Ziwen Yin, Hanyu Cheng, Eleonora Di Valentino +3
Axions that couple to electromagnetism are produced in the early Universe by, among other channels, freeze-in via the Primakoff process. For sufficiently large axion masses, the sa…
Constraining exotic high- reionization histories with Gaussian processes and the Cosmic Microwave Background
Hanyu Cheng, Ziwen Yin, Eleonora Di Valentino +2
The large-angle polarization anisotropies in the Cosmic Microwave Background (CMB) arise from Thomson scattering of CMB photons off free electrons in the post-recombination Univers…
Pressure Parametrization of Dark Energy: First and Second-Order Constraints with Latest Cosmological Data
Hanyu Cheng, Eleonora Di Valentino, Luis A. Escamilla +2
We explore an extension of the CDM model in which the pressure of the dark energy (DE) fluid evolves with the expansion of the Universe, expressed as a function of the scal…