activity
20112026
most citedOn the ground state of quantum graphs with attractive -coupling

30 citations · 108 across the 16 of their papers we have counts for

collaborators

16 papers

math-ph2026

Eigenstates with Infinite Position Moments

Michal Jex

We prove necessary and sufficient conditions for the Schrödinger operators to have zero-energy bound states at the threshold of the essential spectrum such that they have bounded $…

math.SP2023

On the ground state of lattice Schrödinger operators

Michal Jex, František Štampach

We prove necessary and sufficient conditions for lattice Schrödinger operators to have a zero energy bound state in arbitrary dimension. The two criteria are sharp, complementary,…

math-ph2023★ 5 cited

Classical Density Functional Theory: The Local Density Approximation

Michal Jex, Mathieu Lewin, Peter Madsen

We prove that the lowest free energy of a classical interacting system at temperature with a prescribed density profile can be approximated by the local free energy $\in…

math-ph2022

Quantum Systems at The Brink

Dirk Hundertmark, Michal Jex, Markus Lange

We present a method to calculate the asymptotic behavior of eigenfunctions of Schrödinger operators that also works at the threshold of the essential spectrum. It can be viewed as…

math-ph2022★ 2 cited

Classical Density Functional Theory: Representability and Universal Bounds

Michal Jex, Mathieu Lewin, Peter S. Madsen

We provide upper and lower bounds on the lowest free energy of a classical system at given one-particle density . We study both the canonical and grand-canonical cases, assum…

math-ph2021★ 3 cited

Quantum Systems at the Brink: Existence of Bound States, Critical Potentials and Dimensionality

Dirk Hundertmark, Michal Jex, Markus Lange

One of the crucial properties of a quantum system is the existence of bound states. While the existence of eigenvalues below zero, i.e., below the essential spectrum, is well under…

math-ph2020

Quantum Systems at The Brink: Properties of Atomic Bound States at The Ionization Threshold

Dirk Hundertmark, Michal Jex, Markus Lange

We give a rigorous argument that long--range repulsion stabilizes quantum systems; ground states of such quantum systems exist even when the ground state energy is precisely at the…

math.AP2020

Trace Hardy inequality for the Euclidean space with a cut and its applications

Monique Dauge, Michal Jex, Vladimir Lotoreichik

We obtain a trace Hardy inequality for the Euclidean space with a bounded cut , . In this novel geometric setting, the Hardy-type inequality non-typic…

math-ph2019★ 1 cited

Quantum Systems at The Brink. Existence and Decay Rates of Bound States at Thresholds; Atoms

Dirk Hundertmark, Michal Jex, Markus Lange

It is well known that -electron atoms undergoes unbinding for a critical charge of the nucleus , i.e. the atom has eigenstates for the case and it has no bound sta…

math-ph2019★ 2 cited

Quantum Systems at The Brink: Helium-type systems

Dirk Hundertmark, Michal Jex, Markus Lange

In the present paper we study two challenging problems for helium-type systems. Existence of eigenvalues at thresholds and the asymptotic behavior of the corresponding eigenfunctio…

math-ph2018★ 22 cited

The Lieb-Thirring inequality revisited

Rupert L. Frank, Dirk Hundertmark, Michal Jex +1

We provide new estimates on the best constant of the Lieb-Thirring inequality for the sum of the negative eigenvalues of Schrödinger operators, which significantly improve the so f…

math-ph2015★ 8 cited

On absence of bound states for weakly attractive -interactions supported on non-closed curves in

Michal Jex, Vladimir Lotoreichik

Let be a non-closed piecewise- curve, which is either bounded with two free endpoints or unbounded with one free endpoint. Let be t…

math-ph2014★ 19 cited

Spectral asymptotics for interaction supported by a infinite curve

Michal Jex

We consider a generalized Schrödinger operator in describing an attractive interaction in a strong coupling limit. interaction is characterized by a co…

math-ph2014★ 8 cited

Spectral asymptotics of a strong interaction supported by a surface

Pavel Exner, Michal jex

We derive asymptotic expansion for the spectrum of Hamiltonians with a strong attractive interaction supported by a smooth surface in , either infinite and asymptoticall…

math-ph2013★ 8 cited

Spectral asymptotics of a strong interaction on a planar loop

Pavel Exner, Michal Jex

We consider a generalized Schrödinger operator in with an attractive strongly singular interaction of type characterized by the coupling parameter and suppor…

math-ph2011★ 30 cited

On the ground state of quantum graphs with attractive -coupling

Pavel Exner, Michal Jex

We study relations between the ground-state energy of a quantum graph Hamiltonian with attractive coupling at the vertices and the graph geometry. We derive a necessary and suf…