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Xiangyu Zhou

Publications and source records attributed to Xiangyu Zhou.

78 records · Page 5Linked to original sources
arXiv2014

A solution of an $L^{2}$ extension problem with optimal estimate and applications

In this paper, we prove an $L^2$ extension theorem with optimal estimate in a precise way, which implies optimal estimate versions of various well-known $L^2$ extension theorems. As applications, we give proofs of a conjecture of Suita on the equality condition in Suita's conjecture, the so-called $L-$conjecture, and the extended Suita conjecture. As other applications, we give affirmative answer to a question by Ohsawa about limiting case for the extension operators between the weighted Bergman spaces, and we present a relation of our result to Berndtsson's important result on log-plurisubharmonicity of Bergman kernel.

math.CV↗
arXiv2014

Strong openness conjecture and related problems for plurisubharmonic functions

In this article, we solve the strong openness conjecture on the multiplier ideal sheaves for the plurisubharmonic functions posed by Demailly. We prove two conjectures about the growth of the volumes of the sublevel sets of plurisubharmonic functions related to the complex singularity exponents and quasi-plurisubharmonic functions related to the jumping numbers, which were posed by Demailly-Kollár and Jonsson-Mustată respectively. We give a new proof of a lower semicontinuity conjecture posed by Demailly-Kollár without using the ACC conjecture. Other applications by combining with well-known results are also mentioned.

math.CV↗
arXiv2013

Comment on "Direct Measurement of Auger Electrons Emitted from a Semiconductor Light-Emitting Diode under Electrical Injection: Identification of the Dominant Mechanism for Efficiency Droop" [Phys. Rev. Lett. 110, 177406 (2013)]

In a recent letter [Phys. Rev. Lett. 110, 177406 (2013)], presenting a spectroscopic study of the electrons emitted from the GaN p-cap of a forward-biased InGaN/GaN light-emitting diode (LED), the authors observed at least two distinct peaks in the electron energy distribution curves (EDCs), separated by about 1.5 eV, and concluded that the only viable explanation for the higher-energy peak was Auger recombination in the LED active region. We present full-band Monte Carlo simulations suggesting that the higher-energy peaks in the measured EDCs are probably uncorrelated with the carrier distribution in the active region. This would not imply that Auger recombination, and possibily Auger-induced leakage, play a negligible role in LED droop, but that an Auger signature cannot be recovered from the experiment performed on the LED structure under study. We discuss, as an alternative explanation for the observed EDCs, carrier heating by the electric field in the band-bending region.

cond-mat.mes-hall↗
arXiv2013

Full-band electronic structure calculation of semiconductor nanostructures: a reduced-order approach

We propose an efficient reduced-order technique for electronic structure calculations of semiconductor nanostructures, suited for inclusion in full-band quantum transport simulators. The model is based on the linear combination of bulk bands obtained by the empirical pseudopotential method, combined with the use of problem-matched basis functions numerically generated from the singular value decomposition. The efficiency and accuracy of the proposed approach are demonstrated in the case of the dispersion relation of hole subbands in an unstrained GaN layer.

cond-mat.mes-hall↗
arXiv2003

Some results related to group actions in several complex variables

In this talk, we'll present some recent results related to group actions in several complex variables. We'll not aim at giving a complete survey about the topic but giving some our own results and related ones. We'll divide the results into two cases: compact and noncompact transformation groups. We emphasize some essential differences between the two cases. In the compact case, we'll mention some results about schlichtness of envelopes of holomorphy and compactness of automorphism groups of some invariant domains. In the noncompact case, we'll present our solution of the longstanding problem -- the so-called extended future tube conjecture which asserts that the extended future tube is a domain of holomorphy. Invariant version of Cartan's lemma about extension of holomorphic functions from the subvarities in the sense of group actions will be also mentioned.

math.CV↗