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A sharp lower bound for the first Dirichlet eigenvalue of the $p$-laplacian in Gaussian space is derived for sets with prescribed generalized torsional rigidity. The result provides an extension of the classical spectral inequality due to…

Analysis of PDEs · Mathematics 2026-03-31 Francesco Chiacchio , Vincenzo Ferone , Anna Mercaldo , Jing Wang

The long-time maintenance of quantum coherence is crucial for its practical applications. We explore decoherence process of a multiqubit system passing through a correlated channel (phase flip, bit flip, bit-phase flip, and depolarizing).…

Quantum Physics · Physics 2020-02-06 Ming-Liang Hu , Heng Fan

We investigate the utilization of a single generalized dephasing qubit for sensing a quantum reservoir, where the antisymmetric coupling between the qubit and its reservoir is broken. It is found that in addition to the decay factor…

Quantum Physics · Physics 2024-12-02 Ji-Bing Yuan , Zhi-Min Tang , Ya-Ju Song , Shi-Qing Tang , Zhao-Hui Peng , Xin-Wen Wang , Le-Man Kuang

In this paper we extend complex uniform convexity estimates for $\mathbb{C}$ to $ \mathbb{R}^n$ and determine best constants. Furthermore we provide the link to log-Sobolev inequalities and hypercontractivity estimates for ultraspherical…

Functional Analysis · Mathematics 2020-04-14 Paata Ivanisvili , Alexander Lindenberger , Paul F. X. Müller , Michael Schmuckenschläger

We explore covert communication of qubits over the lossy thermal-noise bosonic channel, which is a quantum-mechanical model of many practical channels, including optical. Covert communication ensures that an adversary is unable to detect…

The correlations in quantum networks have attracted strong interest with new types of violations of the locality. The standard Bell inequalities cannot characterize the multipartite correlations that are generated by multiple sources. The…

Quantum Physics · Physics 2018-11-19 Ming-Xing Luo

We discuss quantum entanglement in top pair production at the LHC. Near the $t \bar t$ threshold, entanglement observables are enhanced by suppressing the contribution of $q \bar q$ subprocesses, which is achieved by a simple cut on the…

High Energy Physics - Phenomenology · Physics 2022-08-24 J. A. Aguilar-Saavedra , J. A. Casas

Let $\mathscr{C}_n=\{-1,1\}^n$ be the discrete hypercube equipped with the uniform probability measure $\sigma_n$. We prove that if $(E,\|\cdot\|_E)$ is a Banach space of finite cotype and $p\in[1,\infty)$, then every function…

Functional Analysis · Mathematics 2024-02-21 Dario Cordero-Erausquin , Alexandros Eskenazis

We introduce heterogeneous quantum error-correcting codes composed of qubit types with distinct error channels and study their performance in the code-capacity regime using maximum-likelihood tensor network decoding. In the regime where…

We investigate the possibility of improving the $p$-Poincar\'e inequality $\|\nabla_{\mathbb{H}^N} u\|_p \ge \Lambda_p \|u\|_p$ on the hyperbolic space, where $p>2$ and $\Lambda_p:=[(N-1)/p]^{p}$ is the best constant for which such…

Functional Analysis · Mathematics 2021-08-11 Elvise Berchio , Lorenzo D'Ambrosio , Debdip Ganguly , Gabriele Grillo

In this article we study generalization of the classical Talagrand transport-entropy inequality in which the Wasserstein distance is replaced by the entropic transportation cost. This class of inequalities has been introduced in the recent…

Probability · Mathematics 2019-07-02 Giovanni Conforti , Luigia Ripani

We present an effcient experimental procedure that certifies non vanishing quantum capacities for qubit noisy channels. Our method is based on the use of a fixed bipartite entangled state, where the system qubit is sent to the channel…

Based on the resource theory for quantifying the coherence of quantum channels, we introduce a new coherence quantifier for quantum channels via maximum relative entropy. We prove that the maximum relative entropy for coherence of quantum…

We begin this thesis by expanding the technique of teleportation simulation, which adds noise to the entangled resource state to mimic channel effects. By introducing classical noise in the communication step, we show it is possible to…

Quantum Physics · Physics 2019-04-29 Thomas Cope

Quantum discord is an optimal resource for the quantification of classical and non-classical correlations as compared to other related measures. Geometric measure of quantum discord is another measure of quantum correlations. Recently, the…

Quantum Physics · Physics 2013-08-06 M. Ramzan

We introduce a new analysis technique to derive a single-letter upper bound on the mismatch capacity of a stationary, single-user, memoryless channel with a decoding metric $q$. Our bound is obtained by considering a multicast transmission…

Information Theory · Computer Science 2021-03-29 Anelia Somekh-Baruch

We study quantum channels that are close to another channel with weakly additive Holevo information and derive upper bounds on their classical capacity. Examples of channels with weakly additive Holevo information are entanglement-breaking…

Quantum Physics · Physics 2020-08-25 Felix Leditzky , Eneet Kaur , Nilanjana Datta , Mark M. Wilde

For any quantum discrete memoryless channel, we define a quantity called quantum entanglement capacity with classical feedback ($E_B$), and we show that this quantity lies between two other well-studied quantities. These two quantities -…

Quantum Physics · Physics 2009-11-13 Alan W. Leung

We investigate super dense coding in the presence of noise, i.e. the subsystems of the entangled resource state have to pass a noisy unital quantum channel between the sender and the receiver. We discuss explicitly the case of Pauli…

Quantum Physics · Physics 2015-05-18 Zahra Shadman , Hermann Kampermann , Chiara Macchiavello , Dagmar Bruss

A simple criterion for local equality between the constrained Holevo capacity and the quantum mutual information of a quantum channel is obtained. It implies that the set of all states for which this equality holds is determined by the…

Quantum Physics · Physics 2015-08-04 M. E. Shirokov