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Given an energy-dissipating port-Hamiltonian system, we characterise the exponential decay of the energy via the model ingredients under mild conditions on the Hamiltonian density $\mathcal{H}$. In passing, we obtain generalisations for…

Analysis of PDEs · Mathematics 2024-02-29 Sascha Trostorff , Marcus Waurick

We introduce a supervised dimensionality reduction methodology for categorical (and discretized mixed-type) data based on a density-matrix construction induced by class-conditional frequencies. Given a labeled dataset encoded in a one-hot…

Machine Learning · Statistics 2026-03-03 Raquel Bosch-Romeu , Antonio Falcó , osé-Antonio Rodríguez-Gallego

We deploy algebraic complexity theoretic techniques for constructing symmetric determinantal representations of for00504925mulas and weakly skew circuits. Our representations produce matrices of much smaller dimensions than those given in…

Computational Complexity · Computer Science 2012-10-24 Bruno Grenet , Erich Kaltofen , Pascal Koiran , Natacha Portier

In this study, we introduce a two dimensional complex harmonic oscillator potential with space and time reflection symmetries. The corresponding time independent Schr\"odinger equation yields real eigenvalues with complex eigenfunctions. We…

Quantum Physics · Physics 2020-12-09 Masoumeh Izadparast , S. Habib Mazharimousavi

We present a method that offers perspectives to perform fully antisymmetrized simulations for inhomogeneous bulk fermion matter. The technique bears resemblance to classical periodic boundary conditions, using localized single-particle…

Nuclear Theory · Physics 2011-09-28 Klaas Vantournhout , Natalie Jachowicz , Jan Ryckebusch

We study the repulsive polaron problem in a two-component two-dimensional system of fermionic atoms. We use two different interaction models: a short-range (hard-disk) potential and a dipolar potential. In our approach, all the atoms have…

The well-known TE/TM decomposition of time-harmonic electromagnetic fields in uniaxial anisotropic media is generalized in terms of four-dimensional differential-form formalism by requiring that the field two-form satisfies an orthogonality…

Mathematical Physics · Physics 2015-05-27 Ismo V. Lindell , Luzi Bergamin , Alberto Favaro

An active space variational calculation of the 2-electron reduced density matrix (2-RDM) is derived and implemented where the active orbitals are correlated within the pair approximation. The pair approximation considers only doubly…

Chemical Physics · Physics 2020-10-13 Kade Head-Marsden , David A. Mazziotti

Starting from a Hermitian operator with two distinct eigenvalues, we construct a non-Hermitian bipartite system in Gaussian orthogonal ensemble according to random matrix theory, where we introduce the off-diagonal fluctuations through…

Quantum Physics · Physics 2024-02-28 Chen-Huan Wu

We develop a systematic framework for the spin adaptation of the cumulants of p-particle reduced density matrices (RDMs), with explicit constructions for p = 1 to 3. These spin-adapted cumulants enable rigorous treatment of both S_z and S^2…

Chemical Physics · Physics 2025-10-31 Julia Liebert , Christian Schilling , David A. Mazziotti

The properties of highest-weight representations of the N=2 superconformal algebra in two dimensions can be considerably simplified when re-expressed in terms of relaxed ^sl(2) representations. This applies to the appearance of submodules…

q-alg · Mathematics 2007-05-23 A M Semikhatov

Two field 2-forms on the space-time manifold, in a relationship of duality, are presented and included in the extended phase-space structure used to describe relativistic particles having both electric and magnetic charges. By exterior…

Mathematical Physics · Physics 2010-11-30 M. Grigorescu

A new density matrix and corresponding quantum kinetic equations are introduced for fermions undergoing coherent evolution either in time (coherent particle production) or in space (quantum reflection). A central element in our derivation…

High Energy Physics - Phenomenology · Physics 2009-02-02 Matti Herranen , Kimmo Kainulainen , Pyry Matti Rahkila

In this paper the old problem of determining the discrete spectrum of a multi-particle Hamiltonian is reconsidered. The aim is to bring a fermionic Hamiltonian for large numbers N of particles by analytical means into a shape such that…

Mathematical Physics · Physics 2013-06-13 Joachim Schröter

We consider an electronic bound state of the usual, non-relativistic, molecular Hamiltonian with Coulomb interactions, fixed nuclei, and N electrons (N>1). Near appropriate electronic collisions, we determine the regularity of the…

Mathematical Physics · Physics 2025-08-08 Thierry Jecko , Camille Noûs

We consider a reformulation of QED in which covariant Green functions are used to solve for the electromagnetic field in terms of the fermion fields. It is shown that exact few-fermion eigenstates of the resulting Hamiltonian can be…

Nuclear Theory · Physics 2010-11-26 Jurij W. Darewych , Askold Duviryak

For minimization problems without 2nd derivative information, methods that estimate Hessian matrices can be very effective. However, conventional techniques generate dense matrices that are prohibitive for large problems. Limited-memory…

Optimization and Control · Mathematics 2025-01-22 Johannes J. Brust

We formulate a general sufficiency criterion for discreteness of the spectrum of both supersymmmetric and non-su-persymmetric theories with a fermionic contribution. This criterion allows an analysis of Hamiltonians in complete form rather…

High Energy Physics - Theory · Physics 2012-10-26 Lyonell Boulton , Maria Pilar Garcia del Moral , Alvaro Restuccia

In this paper, we investigate multidimensional first-order quasi-linear systems and find necessary conditions for them to admit Hamiltonian formulation. The insufficiency of the conditions is related to the Poisson cohomology of the…

Exactly Solvable and Integrable Systems · Physics 2024-09-11 Xin Hu , Matteo Casati

This work deals with the problem of strongly correlated electrons in two-dimensions (2D). We give a reduced density matrix (RDM) based tool through which the ground-state energy is given as a functional of the natural orbitals and their…

Strongly Correlated Electrons · Physics 2020-02-26 Ion Mitxelena , Mario Piris