# Arpad Laszlo LukacsDurham University | DU · Department of Mathematical Sciences

Arpad Laszlo Lukacs

Doctor of Philosophy

## About

27

Publications

2,258

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197

Citations

Introduction

Arpad Laszlo Lukacs currently works at the Department of Mathematical Sciences, Durham University. Arpad does research in Theoretical Physics, Mathematical Physics and Quantum Physics.

Additional affiliations

March 2020 - present

**University of the Basque Country UPV/EHU**

Position

- PostDoc Position

Description

- Quantum information science

March 2017 - March 2019

November 2014 - July 2015

Education

September 2004 - March 2011

September 2003 - June 2006

September 2001 - June 2007

## Publications

Publications (27)

We discuss efficient methods to optimize the metrological performance over local Hamiltonians in a bipartite quantum system. For a given quantum state, our methods find the best local Hamiltonian for which the state outperforms separable states the most from the point of view of quantum metrology. We show that this problem can be reduced to maximiz...

We consider quantum metrology with several copies of bipartite and multipartite quantum states. We identify a large class of states that become maximally useful for metrology in the limit of infinite number of copies. The maximally achievable metrological usefulness is attained exponentially fast in the number of copies. We show that, on the other...

In the Abelian Higgs model electric (and magnetic) fields of external charges (and currents) are screened by the scalar field. In this contribution, complementing recent investigations of Ishihara and Ogawa, we present a detailed investigation of charge screening using a perturbative approach with the charge strength as an expansion parameter. It i...

In the Abelian Higgs model electric (and magnetic) fields of external charges (and currents) are screened by the scalar field. In this contribution, complementing recent investigations of Ishihara and Ogawa, we present a detailed investigation of charge screening using a perturbative approach with the charge strength as an expansion parameter. It i...

In a series of recent works, Ishihara and Ogawa have investigated nontopological solitons (Q-balls) in a spontaneously broken Abelian gauge theory coupled to two complex scalar fields. The present paper extends their investigations to the most general U(1)×U(1) symmetric quartic potential. Also, a new class of charged Q-ball solutions with vanishin...

In a series of recent works Ishihara and Ogawa have investigated non-topological solitons (Q-balls) in a spontaneously broken Abelian gauge theory coupled to two complex scalar fields. The present paper extends their investigations to the most general U(1)$\times$U(1) symmetric quartic potential. Also a new class of charged Q-ball solutions with va...

The stability of “visible” electroweak-type cosmic strings is investigated in an extension of the Standard Model by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The visible and dark sectors are coupled through a Higgs-portal and a gauge-kinetic mixing term. It is found that strings whose core is “filled...

The stability of "visible" electroweak-type cosmic strings is investigated in an extension of the Standard Model (SM) by a minimal dark sector, consisting of a U(1) gauge field, broken spontaneously by a scalar. The "visible" and dark sectors are coupled through a Higgs-portal and a gauge-kinetic mixing term. It is found that strings whose core is...

Semilocal and electroweak strings are well-known to be unstable against unwinding by the condensation of the second Higgs component in their cores. A large class of current models of dark matter contains dark scalar fields coupled to the Higgs sector of the Standard Model (Higgs portal) and/or dark U(1) gauge fields. It is shown, that Higgs-portal-...

Twisted non-Abelian flux-Tube solutions are considered in the bosonic sector of a 4-dimensional = 2 super-symmetric gauge theory with U(2)local ×SU(2)global symmetry, with two scalar doublets in the fundamental representation. Twist refers to a time-dependent matrix phase between the two doublets, and twisted strings have nonzero (global) charge, m...

A detailed study of vortices is presented in Ginzburg-Landau (or Abelian Higgs) models with two complex scalars (order parameters) assuming a general U(1)$\times$U(1) symmetric potential. Particular emphasis is given to the case, when only one of the scalars obtains a vacuum expectation value (VEV). It is found that for a significantly large domain...

In a class of two-component Ginzburg-Landau models (TCGL) with a U(1)$\times$U(1) symmetric potential, vortices with a condensate at their core may have significantly lower energies than the Abrikosov-Nielsen-Olesen (ANO) ones. On the example of liquid metallic hydrogen (LMH) above the critical temperature for protons we show that the ANO vortices...

The BPS Skyrme model is a model containing an $SU(2)$-valued scalar field, in which a Bogomol'nyi-type inequality can be satisfied by soliton solutions. In this model, the energy density of static configurations is the sum of the square of the topological charge density plus a potential. The topological charge density is nothing else but the pull-b...

An extended version of the Bogomolny-Prasad-Sommerfeld (BPS) Skyrme model that admits time-dependent solutions is discussed. Initially, by introducing a power law at the original potential term of the BPS Skyrme model, the existence, stability, and structure of the corresponding solutions are investigated. Then, the frequency and half-lifes of the...

An extended version of the BPS Skyrme model that admits time-dependent
solutions is discussed. Initially, by introducing a power law at the original
potential term of the BPS Skyrme model the existence, stability and structure
of the corresponding solutions is investigated. Then, the frequencies and
half-lifes of the radial oscillations of the cons...

Non-Abelian flux-tube (string) solutions carrying global currents are found
in the bosonic sector of 4-dimensional N=2 super-symmetric gauge theories. The
specific model considered here posseses U(2)local x SU(2)global symmetry, with
two scalar doublets in the fundamental representation of SU(2). We construct
string solutions that are stationary an...

We present an effective model, which is an extension of the usual linear
sigma model, that contains a low energy multiplet for every hadronic particle
type. These multiplets are a scalar nonet, a pseudoscalar nonet, a vector
nonet, an axialvector nonet, a baryon octet and a baryon decuplet. Tree level
baryon masses and possible two body decuplet de...

We study string solutions in two-component Abelian Higgs models with
globally U(1) × U(1) symmetric potentials. Two component Abelian
Higgs models with spontaneous symmetry breaking are divided into two
classes, according to the number of Higgs field components obtaining a
nonzero vacuum expectation value. In one class, where one field
component is...

It is shown that in a large class of systems plane waves can act as tractor
beams: i.e., an incident plane wave can exert a pulling force on the scatterer.
The underlying physical mechanism for the pulling force is due to the
sufficiently strong scattering of the incoming wave into another mode having a
larger wave number, in which case excess mome...

A linear stability analysis of twisted flux-tubes (strings) in an SU(2) semilocal theory -- an Abelian-Higgs model with two charged scalar fields with a global SU(2) symmetry -- is carried out. Here the twist refers to a relative phase between the two complex scalars (with linear dependence on, say, the $z$ coordinate), and importantly it leads to...

Quasibreathers (QB) are time-periodic solutions with weak spatial localization introduced in G. Fodor et al. in [ Phys. Rev. D 74 124003 (2006)]. QB’s provide a simple description of oscillons (very long-living spatially localized time dependent solutions). The small amplitude limit of QB’s is worked out in a large class of scalar theories with a g...

The interaction of a kink and a monochromatic plane wave in one dimensional scalar field theories is studied. It is shown that in a large class of models the radiation pressure exerted on the kink is negative, i.e. the kink is {\sl pulled} towards the source of the radiation. This effect has been observed by numerical simulations in the $\phi^4$ mo...

The integrated Sachs-Wolfe (ISW) effect in a Lambda dominated universe can be an important factor in the evolution of cosmic microwave background fluctuations. With the inclusion of cosmological constant we present the complete analytic solution of the covariant linear perturbations of the Einstein equations in the Newtonian gauge, in the case of a...

We examine the possibility of a constraint‐free quantization of linearized gravity, based on the Teukolsky equation for black hole perturbations.
We exhibit a simple quadratic (but complex) Lagrangian for the Teukolsky equation, leading to the interpretation that the elementary excitations (gravitons bound to the Kerr black hole) are unstable.

We present the complete solution of the first order metric and density perturbation equations in a spatially flat (K=0), Friedmann-Robertson-Walker (FRW) universe filled with pressureless ideal fluid, in the presence of cosmological constant. We use covariant linear perturbation formalism and the comoving gauge condition to obtain the field and con...

## Projects

Projects (2)

Investigate scattering phenomena, where scattering of plane waves leads to pulling forces acting on the scatterer