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Related papers: A Dixmier trace formula for the density of states

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We prove perturbation results for traces on normed ideals in semifinite von Neumann algebra factors. This includes the case of Dixmier traces. In particular, we establish existence of spectral shift measures with initial operators being…

Functional Analysis · Mathematics 2015-06-12 Ken Dykema , Anna Skripka

In physics, it is sometimes desirable to compute the so-called \emph{Density Of States} (DOS), also known as the \emph{spectral density}, of a real symmetric matrix $A$. The spectral density can be viewed as a probability density…

Numerical Analysis · Mathematics 2014-10-07 Lin Lin , Yousef Saad , Chao Yang

Recent work [J.S. Lundeen et al. Nature, 474, 188 (2011)] directly measured the wavefunction by weakly measuring a variable followed by a normal (i.e. `strong') measurement of the complementary variable. We generalize this method to mixed…

Quantum Physics · Physics 2012-03-14 Jeff S. Lundeen , Charles Bamber

A new quantum mechanical notion -- Conditional Density Matrix -- is discussed and is applied to describe some physical processes. This notion is a natural generalization of von Neumann density matrix for such processes as divisions of…

Quantum Physics · Physics 2007-05-23 V. V. Belokurov , O. A. Khrustalev , V. A. Sadovnichy , O. D. Timofeevskaya

The measurement statistics for spatial and temporal quantum processes are produced through distinct mechanisms. Measurements that are space-like separated exhibit non-signaling behavior. However, time-like separated measurements can only…

Quantum Physics · Physics 2024-08-30 Zhian Jia , Dagomir Kaszlikowski

1-Dimensional (1D) photonics crystals with and without defects have been numerically studied using efficient Transfer Matrix Method (TMM). Detailed numerical recipe of the TMM has been laid out. Dispersion relation is verified for the…

Classical Physics · Physics 2020-07-16 Shaolin Liao , Lu Ou

In the present paper, we give a simple proof of the level density of fixed trace square ensemble.We derive the integral equation of the level density of fixed trace square ensemble.Then we analyze the asymptotic behavior of the level…

Mathematical Physics · Physics 2008-04-16 Da Xu , Lihe Wang

A new approach to the Helmholtz spectrum for arbitrarily shaped boundaries and a rather general class of boundary conditions is introduced. We derive the boundary induced change of the density of states in terms of the free Green's function…

Statistical Mechanics · Physics 2009-11-11 Thorsten Emig

An addition rule of impure density operators, which provides a pure state density operator, is formulated. Quantum interference including visibility property is discussed in the context of the density operator formalism. A measure of…

Quantum Physics · Physics 2009-11-07 Vladimir I Man'ko , Giuseppe Marmo , E C George Sudarshan , Francesco Zaccaria

We study the single particle density of states of a one-dimensional speckle potential, which is correlated and non-Gaussian. We consider both the repulsive and the attractive cases. The system is controlled by a single dimensionless…

Disordered Systems and Neural Networks · Physics 2015-02-26 G. M. Falco , Andrei A. Fedorenko , Jacopo Giacomelli , Michele Modugno

We study the Dirac equation in confining potentials with pure vector coupling, proving the existence of metastable states with longer and longer lifetimes as the non-relativistic limit is approached and eventually merging with continuity…

High Energy Physics - Theory · Physics 2008-12-18 R. Giachetti , E. Sorace

Models of neutron stars are considered in the case of a uniform density distribution. An algebraic equation, valid for any equation of state, is obtained. This equation allows one to find the approximate mass of a star of a given density…

High Energy Astrophysical Phenomena · Physics 2023-11-14 G. S. Bisnovatyi-Kogan , E. A. Patraman

Josza's definition of fidelity for a pair of (mixed) quantum states is studied in the context of two types of operator algebras. The first setting is mainly algebraic in that it involves unital C$^*$-algebras $A$ that possess a faithful…

Quantum Physics · Physics 2016-11-23 Douglas Farenick , Samuel Jaques , Mizanur Rahaman

Perhaps surprisingly, recent studies have shown probabilistic model likelihoods have poor specificity for out-of-distribution (OOD) detection and often assign higher likelihoods to OOD data than in-distribution data. To ameliorate this…

We study finitely additive extensions of the asymptotic density to all the subsets of natural numbers. Such measures are called density measures. We consider a class of density measures constructed from free ultrafilters on $\mathbb{N}$ and…

Number Theory · Mathematics 2016-01-26 Ryoichi Kunisada

We define a linear functional, the DOS functional, on spaces of holomorphic functions on the unit disk which is associated with random ergodic contraction operators on a Hilbert space, in analogy with the density of state functional for…

Mathematical Physics · Physics 2015-03-06 Alain Joye

We study the measurement for the unambiguous discrimination of two mixed quantum states that are described by density operators $\rho_1$ and $\rho_2$ of rank d, the supports of which jointly span a 2d-dimensional Hilbert space. Based on two…

Quantum Physics · Physics 2009-11-13 Ulrike Herzog

This paper considers the problem of specifying a simple approximating density function for a given data set (x_1,...,x_n). Simplicity is measured by the number of modes but several different definitions of approximation are introduced. The…

Statistics Theory · Mathematics 2007-06-13 P. Laurie Davies , Arne Kovac

We introduce a new class of quantum many-particle entangled states, called the Dicke squeezed (or DS) states, which can be used to improve the precision in quantum metrology beyond the standard quantum limit. We show that the enhancement in…

Quantum Physics · Physics 2015-06-22 Zhen Zhang , Luming Duan

Given a pure state vector |x> and a density matrix rho, the function p(x|rho)=<x|rho|x> defines a probability density on the space of pure states parameterised by density matrices. The associated Fisher-Rao information measure is used to…

Quantum Physics · Physics 2011-06-03 Dorje C. Brody