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Related papers: Comment on the Ghost State in the Lee Model

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We argue that if de Sitter space is indeed represented by a finite dimensional quantum system, then semi-classical considerations, combined with the fundamental principles of quantum measurement theory, imply that any theoretical model of…

High Energy Physics - Theory · Physics 2026-05-14 Tom Banks

Quantum Hoare logic allows us to reason about quantum programs. We present an extension of quantum Hoare logic that introduces "ghost variables" to extend the expressive power of pre-/postconditions. Ghost variables are variables that do…

Quantum Physics · Physics 2019-02-04 Dominique Unruh

We discuss the variational method used in lattice spectroscopy calculations. In particular we address the role of ghost contributions which appear in quenched or partially quenched simulations and have a non-standard euclidean time…

High Energy Physics - Lattice · Physics 2009-11-11 Tommy Burch , Christof Gattringer , Leonid Ya. Glozman , Christian Hagen , C. B. Lang

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Yu-Ping Teng , Wolung Lee , Kin-Wang Ng

We study the influence rules of the speckle size of light source on ghost imaging, and propose a new type of speckle patterns to improve the quality of ghost imaging. The results show that the image quality will first increase and then…

In a systematic way, we investigate a widely asked question: Do LLMs really understand what they say?, which relates to the more familiar term Stochastic Parrot. To this end, we propose a summative assessment over a carefully designed…

Computation and Language · Computer Science 2025-02-14 Mo Yu , Lemao Liu , Junjie Wu , Tsz Ting Chung , Shunchi Zhang , Jiangnan Li , Dit-Yan Yeung , Jie Zhou

We present a novel way to constrain the ghost field with respect to other physical fields present in a given theory such that the theory becomes quantizable. This is achieved by imposing positivity of the total kinetic energy of the system…

High Energy Physics - Theory · Physics 2024-10-24 Sukanta Panda , Archit Vidyarthi

Language models are susceptible to bias, sycophancy, backdoors, and other tendencies that lead to unfaithful responses to the input context. Interpreting internal states of language models could help monitor and correct unfaithful behavior.…

Computation and Language · Computer Science 2024-12-10 Jiahai Feng , Stuart Russell , Jacob Steinhardt

We introduce the notions of semi-uniform input-to-state stability and its subclass, polynomial input-to-state stability, for infinite-dimensional systems. We establish a characterization of semi-uniform input-to-state stability based on…

Optimization and Control · Mathematics 2022-05-30 Masashi Wakaiki

The aim of these notes is to provide a self-contained review of why it is generically a problem when a solution of a theory possesses ghost fields among the perturbation modes. We define what a ghost field is and we show that its presence…

High Energy Physics - Theory · Physics 2018-05-18 Fulvio Sbisà

A vacuum instability due to a massless ghost in a hidden sector can lead to an effective equation of state for dark energy that changes smoothly from $w=-3/2$ at large redshifts, to $w\approx-1.2$ today, to $w=-1$ in the future. We discuss…

High Energy Physics - Theory · Physics 2016-09-06 B. Holdom

We investigate the stability against inhomogeneous perturbations and the appearance of ghost modes in Gauss-Bonnet gravitational theories with a non-minimally coupled scalar field, which can be regarded as either the dilaton or a…

High Energy Physics - Theory · Physics 2008-11-26 Gianluca Calcagni , Beatriz de Carlos , Antonio De Felice

Recent LHC results concerning the mass of the Higgs boson indicate that the vacuum in our Universe may be unstable. We analyze properties of unstable vacuum states from the point of view of the quantum theory of unstable states. From the…

General Physics · Physics 2013-06-20 K. Urbanowski

We consider dynamics of hidden variables for measurements in a generalized bell-type model for a single spin using natural assumptions. The evolution of the system, which can be expressed as dynamic chaos is studied. The equilibrium state…

Quantum Physics · Physics 2008-12-31 Yu. I. Bogdanov

In the realm of a quantum cosmological model for dark energy in which we have been able to construct a well-defined Hilbert space, a consistent coherent state representation has been formulated that may describe the quantum state of the…

General Relativity and Quantum Cosmology · Physics 2007-09-24 S. Robles-Perez , Y. Hassouni , P. F. Gonzalez-Diaz

Very recently we present a theory to discuss the nature of light and show that the quantization of light energy in vacuum can be derived directly from classical electromagnetic theory. In the theory a key concept of stability of statistical…

Optics · Physics 2007-05-23 Wei-Long She

In this paper, we point out thermodynamical description of ghost dark energy and its generalization to the early universe. Thereinafter, we find expressions for the entropy changes of these dark energy candidates. In addition, considering…

General Relativity and Quantum Cosmology · Physics 2015-05-06 M. Honarvaryan , A. Sheykhi , H. Moradpour

The key observation about quantum reality is that it often appears as if, at some moment, the probability of a quantum event becomes a definite outcome for us. A careful analysis suggests, however, that what we perceive as a definite state…

General Physics · Physics 2025-10-22 Aleksandar Perisic

In this paper, we present necessary and sufficient conditions under which a linear time-invariant (LTI) system is state feedback equivalent to a negative imaginary (NI) system. More precisely, we show that a minimal LTI strictly proper…

Systems and Control · Electrical Eng. & Systems 2021-09-24 Kanghong Shi , Ian R. Petersen , Igor G. Vladimirov

We study the relativistic Lee model on static Riemannian manifolds. The model is constructed nonperturbatively through its resolvent, which is based on the so-called principal operator and the heat kernel techniques. It is shown that making…

High Energy Physics - Theory · Physics 2011-03-24 Burak Tevfik Kaynak , Osman Teoman Turgut
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