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Related papers: Relative Entropy in CFT

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We study the ratio of the entropy to the total energy in conformal field theories at finite temperature. For the free field realizations of N=4 super Yang-Mills theory in D=4 and the (2,0) tensor multiplet in D=6, the ratio is bounded from…

High Energy Physics - Theory · Physics 2007-05-23 George Siopsis

We study the relative R\'enyi entropy (RRE) under local quenches in two-dimensional conformal field theories (CFTs), focusing on rational CFTs (RCFTs) and holographic CFTs. In RCFTs, the RRE evolves as a monotonic function over time,…

High Energy Physics - Theory · Physics 2025-12-22 Zi-Xuan Zhao , Song He , Hao Ouyang , Hong-an Zeng , Yu-Xuan Zhang

We continue our study of reflected entropy, $R(A,B)$, for Gaussian systems. In this paper we provide general formulas valid for free scalar fields in arbitrary dimensions. Similarly to the fermionic case, the resulting expressions are fully…

High Energy Physics - Theory · Physics 2020-12-30 Pablo Bueno , Horacio Casini

We study the Renyi and entanglement entropies for free 2d CFT's at finite temperature and finite size, with emphasis on their properties under modular transformations of the torus. We address the issue of summing over fermion spin…

High Energy Physics - Theory · Physics 2015-06-04 Sagar Fakirchand Lokhande , Sunil Mukhi

In this paper we study the properties of two-dimensional CFTs defined by cyclic and symmetric orbifolds of free Dirac fermions, especially by focusing on the partition function and entanglement entropy. Via the bosonization, we construct…

High Energy Physics - Theory · Physics 2022-12-21 Tadashi Takayanagi , Takashi Tsuda

We point out that the entropy of (near) extremal black holes can be interpreted as the entanglement entropy of dual conformal quantum mechanics via AdS2/CFT1. As an explicit example, we study near extremal BTZ black holes and derive this…

High Energy Physics - Theory · Physics 2008-11-26 Tatsuo Azeyanagi , Tatsuma Nishioka , Tadashi Takayanagi

Quantum impurities give rise to rich physical phenomena, with some exhibiting critical behavior described by conformal field theories (CFTs) in the low-energy limit. In parallel, party-time ($\mathcal{PT}$) symmetric non-Hermitian systems…

Quantum Physics · Physics 2025-02-19 Heng-Hsi Li , Kuang-Hung Chou , Xueda Wen , Po-Yao Chang

In this paper, we first study mutual information of excited states in the small subsystem size limit in generic conformal field theory. We then discuss relative entropy of two disjoint subsystems in the same limit.

High Energy Physics - Theory · Physics 2017-11-22 Tomonori Ugajin

In this note, we use entanglement entropy as a tool to explore the universal properties of CFTs dual to extremal BTZ black holes. We demonstrate that the entanglement entropies computed in the CFTs at the boundary of the extremal BTZ and…

High Energy Physics - Theory · Physics 2014-02-26 Pawel Caputa , Vishnu Jejjala , Hesam Soltanpanahi

Entanglement entropy in even dimensional conformal field theories (CFTs) contains well-known universal terms arising from the conformal anomaly. Renyi entropies are natural generalizations of the entanglement entropy that are much less…

High Energy Physics - Theory · Physics 2014-06-25 Jeongseog Lee , Lauren McGough , Benjamin R. Safdi

The concept of distinguishability lies at the heart of quantum information theory. We introduce \textit{left-right relative entropy} as a quantitative measure of distinguishability within the space of boundary states in two-dimensional…

High Energy Physics - Theory · Physics 2026-05-26 Mostafa Ghasemi

We derive the entanglement entropy of chiral fermions on the circle at arbitrary temperature. The spin-sector contribution depends only on the total length of the entangling region, regardless of the configuration of the intervals. Thus…

High Energy Physics - Theory · Physics 2019-11-27 Pascal Fries , Ignacio A. Reyes

The fermionic relative entropy in two-dimensional Rindler spacetime is studied using both modular theory and the reduced one-particle density operators. The methods and results are compared. A formula for the relative entropy for general…

Mathematical Physics · Physics 2026-03-23 Felix Finster , Albert Much

The relative entropy is a measure of the distinguishability of two quantum states. A great deal of progress has been made in the study of the relative entropy between an excited state and the vacuum state of a conformal field theory (CFT)…

High Energy Physics - Theory · Physics 2019-11-25 Ning Bao , Mudassir Moosa , Ibrahim Shehzad

The fermionic von Neumann entropy, the fermionic entanglement entropy and the fermionic relative entropy are defined for causal fermion systems. Our definition makes use of entropy formulas for quasi-free fermionic states in terms of the…

Mathematical Physics · Physics 2025-04-16 Felix Finster , Robert H. Jonsson , Magdalena Lottner , Albert Much , Simone Murro

We give a general formula for the relative entropy between the vacuum state and a coherent state, that is a state obtained by applying an exponentiated stress energy tensor to the vacuum of a chiral conformal field theory on the lightray.…

Mathematical Physics · Physics 2020-07-15 Lorenzo Panebianco

Extending our previous work, we study the relative entropy between the reduced density matrices obtained from globally excited states in conformal field theories of arbitrary dimensions. We find a general formula in the small subsystem size…

High Energy Physics - Theory · Physics 2017-03-08 Gábor Sárosi , Tomonori Ugajin

Inspired by the holographic computation of large interval entanglement entropy of two dimensional conformal field theory at high temperature, it was proposed that the thermal entropy is related to the entanglement entropy as…

High Energy Physics - Theory · Physics 2015-05-01 Bin Chen , Jie-qiang Wu

In this paper we calculate the entanglement entropy of two coupled gapless systems in general spatial dimension d. The gapless systems can be either conformal field theories (CFT), or Fermi liquids. We assume the two systems are coupled…

Strongly Correlated Electrons · Physics 2015-05-27 Cenke Xu

We consider a conformal field theory in two dimensions in which an external perturbation is placed. We study the energy flux and entanglement entropy for one, two and multiple intervals and give a suggestion relating the two in some cases.…

High Energy Physics - Theory · Physics 2017-11-01 Talya Vaknin