arXiv subjects

Gaoyuan Wang

Publications and source records attributed to Gaoyuan Wang.

4 recordsLinked to original sources

arXiv2025

Efficient Privacy-Preserving Training of Quantum Neural Networks by Using Mixed States to Represent Input Data Ensembles

Quantum neural networks (QNNs) are gaining increasing interest due to their potential to detect complex patterns in data by leveraging uniquely quantum phenomena. This makes them particularly promising for biomedical applications. In these applications and in other contexts, increasing statistical power often requires aggregating data from multiple participants. However, sharing data, especially sensitive information like personal genomic sequences, raises significant privacy concerns. Quantum federated learning offers a way to collaboratively train QNN models without exposing private data. However, it faces major limitations, including high communication overhead and the need to retrain models when the task is modified. To overcome these challenges, we propose a privacy-preserving QNN training scheme that utilizes mixed quantum states to encode ensembles of data. This approach allows for the secure sharing of statistical information while safeguarding individual data points. QNNs can be trained directly on these mixed states, eliminating the need to access raw data. Building on this foundation, we introduce protocols supporting multi-party collaborative QNN training applicable across diverse domains. Our approach enables secure QNN training with only a single round of communication per participant, provides high training speed and offers task generality, i.e., new analyses can be conducted without reacquiring information from participants. We present the theoretical foundation of our scheme's utility and privacy protections, which prevent the recovery of individual data points and resist membership inference attacks as measured by differential privacy. We then validate its effectiveness on three different datasets with a focus on genomic studies with an indication of how it can used in other domains without adaptation.

quant-ph↗

arXiv2025

$ζ$-QVAE: A Quantum Variational Autoencoder utilizing Regularized Mixed-state Latent Representations

A major challenge in quantum computing is its application to large real-world datasets due to scarce quantum hardware resources. One approach to enabling tractable quantum models for such datasets involves finding low-dimensional representations that preserve essential information for downstream analysis. In classical machine learning, variational autoencoders (VAEs) facilitate efficient data compression, representation learning for subsequent tasks, and novel data generation. However, no quantum model has been proposed that captures these features for direct application to quantum data on quantum computers. Some existing quantum models for data compression lack regularization of latent representations. Others are hybrid models with only some internal quantum components, impeding direct training on quantum data. To address this, we present a fully quantum framework, $ζ$-QVAE, which encompasses all the capabilities of classical VAEs and can be directly applied to map both classical and quantum data to a lower-dimensional space, while effectively reconstructing much of the original state from it. Our model utilizes regularized mixed states to attain optimal latent representations. It accommodates various divergences for reconstruction and regularization. Furthermore, by accommodating mixed states at every stage, it can utilize the full-data density matrix and allow for a training objective defined on probabilistic mixtures of input data. Doing so, in turn, makes efficient optimization possible and has potential implications for private and federated learning. In addition to exploring the theoretical properties of $ζ$-QVAE, we demonstrate its performance on genomics and synthetic data. Our results indicate that $ζ$-QVAE learns representations that better utilize the capacity of the latent space and exhibits similar or better performance compared to matched classical models.

quant-ph↗

arXiv2016

Random Functions via Dyson Brownian Motion: Progress and Problems

We develope a computationally efficient extension of the Dyson Brownian Motion (DBM) algorithm to generate random function in C2 locally. We further explain that random functions generated via DBM show an unstable growth as the traversed distance increases. This feature restricts the use of such functions considerably if they are to be used to model globally defined ones. The latter is the case if one uses random functions to model landscapes in string theory. We provide a concrete example, based on a simple axionic potential often used in cosmology, to highlight this problem and also offer an ad hoc modification of DBM that suppresses this growth to some degree.

hep-th↗

arXiv2016

Vacuum Selection on Axionic Landscapes

We compute the distribution of minima that are reached dynamically on multi-field axionic landscapes, both numerically and analytically. Such landscapes are well suited for inflationary model building due to the presence of shift symmetries and possible alignment effects (the KNP mechanism). The resulting distribution of dynamically reached minima differs considerably from the naive expectation based on counting all vacua. These differences are more pronounced in the presence of many fields due to dynamical selection effects: while low lying minima are preferred as fields roll down the potential, trajectories are also more likely to get trapped by one of the many nearby minima. We show that common analytic arguments based on random matrix theory in the large $D$-limit to estimate the distribution of minima are insufficient for quantitative arguments pertaining to the dynamically reached ones. This discrepancy is not restricted to axionic potentials. We provide an empirical expression for the expectation value of such dynamically reached minimas' height and argue that the cosmological constant problem is not alleviated in the absence of anthropic arguments. We further comment on the likelihood of inflation on axionic landscapes in the large D-limit.

hep-th↗