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Related papers: Spectral properties of ghost Neumann matrices

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We study an approximate version of the Schwinger-Dyson equation that controls the nonperturbative behavior of the ghost-gluon vertex, in the Landau gauge. In particular, we focus on the form factor that enters in the dynamical equation for…

High Energy Physics - Phenomenology · Physics 2013-08-16 A. C. Aguilar , D. Ibáñez , J. Papavassiliou

It is well known that, in Landau gauge, the renormalization function of the ghost-ghost-gluon vertex \widetilde{Z}_1(p^2) is finite and constant, at least to all orders of perturbation theory. On the other hand, a direct non-perturbative…

High Energy Physics - Lattice · Physics 2009-11-10 A. Mihara , A. Cucchieri , T. Mendes

The existence of a ground ring of ghost number zero operators in the chiral BRST cohomology of the N=2 string is used to derive an infinite set of Ward identities for the closed-string scattering amplitudes at arbitrary genus. These…

High Energy Physics - Theory · Physics 2009-10-31 Klaus Junemann , Olaf Lechtenfeld

Gutzwiller's semiclassical trace formula for the density of states in a chaotic system diverges near bifurcations of periodic orbits, where it must be replaced with uniform approximations. It is well known that, when applying these…

Chaotic Dynamics · Physics 2009-10-31 T. Bartsch , J. Main , G. Wunner

In this article a new solution of the Einstein-Dirac's equations is presented. There are ghost spinors, i.e. the stress-energy tensor is equal to zero and the current of these fields is non-zero vector. Last the ghost neutrino was found.…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Elena V. Palesheva

Thermal duality is a relationship between the behaviour of heterotic string models of the $E(8)x E(8)$ or $SO(32)$ types at inversely related temperatures, a variant of T duality in the Euclidean regime. This duality would have consequences…

High Energy Physics - Theory · Physics 2015-09-17 Michael Hewitt

We consider the inverse eigenvalue problem for entanglement witnesses, which asks for a characterization of their possible spectra (or equivalently, of the possible spectra resulting from positive linear maps of matrices). We completely…

Quantum Physics · Physics 2018-04-02 Nathaniel Johnston , Everett Patterson

We study the ghost sector of vacuum string field theory where the BRST operator Q is given by the midpoint insertion proposed by Gaiotto, Rastelli, Sen and Zwiebach. We introduce a convenient basis of half-string modes in terms of which Q…

High Energy Physics - Theory · Physics 2009-11-07 Robertus Potting , Joris Raeymaekers

Spectral features are widely incorporated within Graph Neural Networks (GNNs) to improve their expressive power, or their ability to distinguish among non-isomorphic graphs. One popular example is the usage of graph Laplacian eigenvectors…

Machine Learning · Computer Science 2025-09-29 Snir Hordan , Maya Bechler-Speicher , Gur Lifshitz , Nadav Dym

We test oscillator level truncation regularization in string field theory by calculating descent relations among vertices, or equivalently, the overlap of wedge states. We repeat the calculation using bosonic, as well as fermionic ghosts,…

High Energy Physics - Theory · Physics 2008-11-26 Ehud Fuchs , Michael Kroyter

Parameter-dependent statistical properties of spectra of totally connected irregular quantum graphs with Neumann boundary conditions are studied. The autocorrelation functions of level velocities c(x) and c(w,x) as well as the distributions…

Chaotic Dynamics · Physics 2009-07-17 Oleh Hul , Petr Seba , Leszek Sirko

A theory of random-matrix bases is presented, including expressions for orthogonality, completeness and the random-matrix synthesis of arbitrary matrices. This is applied to ghost imaging as the realization of a random-basis reconstruction,…

Image and Video Processing · Electrical Eng. & Systems 2018-06-27 David Ceddia , David M. Paganin

Nonlinear systems driven by noise and periodic forces with more than one frequency exhibit the phenomenon of Ghost Stochastic Resonance (GSR) found in a wide and disparate variety of fields ranging from biology to geophysics. The common…

Disordered Systems and Neural Networks · Physics 2015-05-30 Pablo Balenzuela , Holger Braun , Dante R. Chialvo

Assessing the presence of chemical, biological, radiological and nuclear threats is a crucial task which is usually dealt with by analyzing the presence of spectral features in a measured absorption profile. The use of quantum light allows…

We review the history of the ghost problem in quantum field theory from the Pauli-Villars regulator theory to currently popular fourth-order derivative quantum gravity theories. While these theories all appear to have unitarity-violating…

High Energy Physics - Theory · Physics 2021-02-03 Philip D. Mannheim

We revisit ghost dark matter, the possibility that ghost condensation may serve as an alternative to dark matter. In particular, we investigate the Friedmann-Robertson-Walker (FRW) background evolution and the large-scale structure (LSS) in…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Tomonori Furukawa , Shuichiro Yokoyama , Kiyotomo Ichiki , Naoshi Sugiyama , Shinji Mukohyama

In this paper, we systematically study the "ghost" symmetry in the CKP hierarchy through its actions on the Lax operator, dressing operator, eigenfunctions and the tau function. In this process, the spectral representation of the…

Exactly Solvable and Integrable Systems · Physics 2015-06-18 Jipeng Cheng , Jingsong He

In arXiv:1410.7268v3, the authors consider eigenvalues of overlapping Wishart matrices and prove that its fluctuations asymptotically convergence to the Gaussian free field. In this brief note, their result is extended to show that when the…

Probability · Mathematics 2021-12-28 Jeffrey Kuan , Zhengye Zhou

We prove a no-ghost theorem for a bosonic string propagating in Nappi-Witten spacetime. This is achieved in two steps. We first demonstrate unitarity for a class of NW/U(1) modules: the norm of any state which is primary with respect to a…

High Energy Physics - Theory · Physics 2009-10-29 Gang Chen , Yeuk-Kwan E. Cheung , Zheyong Fan , Jens Fjelstad , Stephen Hwang

Nonlinear eigenvalue problems for pairs of homogeneous convex functions are particular nonlinear constrained optimization problems that arise in a variety of settings, including graph mining, machine learning, and network science. By…

Optimization and Control · Mathematics 2022-09-15 Francesco Tudisco , Dong Zhang