Results for "Marcin Pawłowski"

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The influence of the choice of post-processing method on Bell inequalitiesOct 19 2017Dec 07 2017In every experimental test of a Bell inequality, we are faced with the problem of inefficient detectors. How we treat the events when no particle was detected has a big influence on the properties of the inequality. In this work, we study this influence. ... More
Testing dimension and non-classicality in communication networksMay 07 2015Sep 14 2015We consider networks featuring preparation, transformation, and measurement devices, in which devices exchange communication via mediating physical systems. We investigate the problem of testing the dimension of the mediating systems in the device-independent ... More
Superfast Algorithms and the Halting Problem in Geometric AlgebraNov 05 2006A new type of algorithms is presented that combine the advantages of quantum and classical ones. Those combined advantages along with aspects of Geometric Algebra that open possibilities unavailable to both of these computations are exploited to obtain ... More
Structure of quantum and broadcasting nonlocal correlationsApr 20 2015Jan 03 2016The multipartite setting offers much more complexity of nonlocality than the bipartite one. We analyze the structure of tripartite nonlocal correlations by proposing inequalities satisfied by each type: bilocal, broadcasting and quantum, but violated ... More
Robustness of quantum randomness expansion protocols in the presence of noiseMay 01 2013In this paper we investigate properties of several randomness generation protocols in the device independent framework. Using Bell-type inequalities it is possible to certify that the numbers generated by an untrusted device are indeed random. We present ... More
Experimentally feasible semi-device-independent certification of $4$ outcome POVMsNov 30 2018In this paper we construct a semi-device-independent protocol able to certify the presence of the generalized measurements. We show robustness of the protocol and conclude that it allows for experimental realisations using current technology.
Information CausalityDec 06 2011We review the literature on Information Causality. Since it's for a book, we don't think an abstract will be needed at all, so we have written this one just for the sake of the arXiv.
Geometric time in quantum cosmologyMar 16 2014Various choices of the geometry degrees of freedom as the emergent time are tested on the model of an isotropic universe with a scalar field of $\phi^2$ potential. Potential problems with each choices as well as possible applications in loop quantization ... More
Self-testing of unsharp measurementsMar 29 2019We consider unsharp quantum measurements as a recourse in scenarios where one faces the trade-off between information gain and disturbance. We analyse in detail the case of two-outcome qubit measurements and show that generalized measurements allow for ... More
Properties of dimension witnesses and their semi-definite programming relaxationsMay 15 2014In this paper we develop a method for investigating semi-device-independent randomness expansion protocols that was introduced in [Li et al., Phys. Rev. A $\mathbf{87}$, 020302(R) (2013)]. This method allows to lower-bound, with semi-definite programming, ... More
State independent contextuality advances one-way communicationAug 16 2017Apr 29 2018Despite 'quantum contextuality' being one of the most fundamental non-classical features, its generic role in information processing and computation is an open quest. This article shows that quantum contextuality is a potential resource for communication. ... More
Device-independent quantum key distribution based on measurement inputsAug 29 2013May 17 2015We provide an analysis of a new family of device independent quantum key distribution (QKD) protocols with several novel features: (a) The bits used for the secret key do not come from the results of the measurements on an entangled state but from the ... More
Connections Between Mutually Unbiased Bases and Quantum Random Access CodesSep 14 2017Mar 28 2018We present a new quantum communication complexity protocol, the promise--Quantum Random Access Code, which allows us to introduce a new measure of unbiasedness for bases of Hilbert spaces. The proposed measure possesses a clear operational meaning and ... More
When Are Popescu-Rohrlich Boxes and Random Access Codes Equivalent?Jul 30 2013Sep 11 2014We study a problem of interconvertibility of two supra-quantum resources: one is so called PR-box, which violates CHSH inequality up to maximal algebraic bound, and second is so called random access code (RAC). The latter is a functionality that enables ... More
Device independent witness of arbitrary dimensional quantum systems employing binary outcome measurementsMar 14 2018Jan 04 2019Device independent dimension witnesses (DW) are a remarkable way to test the dimension of a quantum system in a prepare-and-measure scenario imposing minimal assumptions on the internal features of the devices. However, as the dimension increases, the ... More
Quantum nonlocality via local contextuality with qubit-qubit entanglementJul 30 2015Apr 30 2016Quantum nonlocality can be revealed "via local contextuality" in qudit-qudit entangled systems with $d > 2$, that is, through the violation of inequalities containing Alice-Bob correlations that admit a local description, and Alice-Alice correlations ... More
A classical-quantum hybrid oracle architecture for Boolean oracle identification in the noisy intermediate-scale quantum eraMay 14 2019Quantum algorithms have the potential to be very powerful. However, to exploit quantum parallelism, some quantum algorithms require an embedding of large classical data into quantum states. This embedding can cost a lot of resources, for instance by implementing ... More
Electron spin rotations induced by oscillating Rashba interaction in a quantum wireSep 30 2015Dec 10 2015A novel method and nanodevice are introduced that allows to rotate the single electron spin confined in a gated electrostatic InSb nanowire quantum dot. Proposed method does not require application of any (oscillating or static) external magnetic fields. ... More
Quantum-mechanical machinery for rational decision-making in classical guessing gameAug 20 2015Nov 23 2015In quantum game theory, one of the most intriguing and important questions is, "Is it possible to get quantum advantages without any modification of the classical game?" The answer to this question so far has largely been negative. So far, it has usually ... More
Semi-device independent random number expansion protocol with n to 1 quantum random access codesSep 24 2011Mar 13 2012We study random number expansion protocols based on the $n \to 1$ quantum random access codes (QRACs). We consider them in the semi-device independent scenario where the inner workings of the devices are unknown to us but we can certify the dimensions ... More
Entanglement storage by classical fixed points in the two-axis countertwisting modelNov 30 2015We analyze a scheme for storage of entanglement quantified by the quantum Fisher information in the two-axis countertwisting model. A characteristic feature of the two-axis countertwisting Hamiltonian is the existence of the four stable center and two ... More
Generation of spin-dependent coherent states in a quantum wireFeb 26 2016Jul 08 2016We propose an all-electrically controlled nanodevice - a gated semiconductor nanowire - capable of generating a coherent state of a single electron trapped in a harmonic oscillator or superposition of such coherent states - the Schr\"odinger cat state. ... More
Free randomness amplification using bipartite chain correlationsMar 22 2013A direct analysis of the protocol of randomness amplification using Bell inequality violation is performed in terms of the convex combination of no-signaling boxes required to simulate quantum violation of the inequality. The probability distributions ... More
Many-body effects in quantum metrologyOct 08 2018Oct 17 2018We study the impact of many-body effects on the fundamental precision limits in quantum metrology. On the one hand such effects may lead to non-linear Hamiltonians, studied in the field of non-linear quantum metrology, while on the other hand they may ... More
Electron spin separation without magnetic fieldSep 23 2013Feb 24 2014A nanodevice capable of separating spins of two electrons confined in a quantum dot formed in a gated semiconductor nanowire is proposed. Two electrons confined initially in a single quantum dot in the singlet state are transformed into the system of ... More
Generation of Schrödinger's cat states in a planar semiconductor heterostructureOct 20 2016We propose a nanodevice based on a typical planar semiconductor heterostructure with lateral confinement potential created by voltages applied to local electrodes. We show how to obtain near parabolical confinement along the nanodevice, and how to use ... More
Experimental quantum randomness generation invulnerable to the detection loopholeOct 13 2014Oct 28 2014Random numbers are essential for multiple applications, including cryptography, financial security, digital rights management and scientific simulations. However, producing random numbers from a finite state machine, such as a classical computer, is impossible. ... More
Irregular Labellings of Circulant GraphsNov 01 2011We investigate the \textit{irregularity strength} ($s(G)$) and \textit{total vertex irregularity strength} ($tvs(G)$) of circulant graphs $Ci_n(1,2,...,k)$ and prove that $tvs(Ci_n(1,2,...,k))=\lceil\frac{n+2k}{2k+1}\rceil$, while $s(Ci_n(1,2,...,k))=\lceil\frac{n+2k-1}{2k}\rceil$ ... More
Two-particle system in Coulomb potential for twist-deformed space-timeJul 11 2018In this article, we define two-particle system in Coulomb potential for twist-deformed space-time with spatial directions commuting to time-dependent function $f_{\kappa_a}({t})$. Particularly, we provide the proper Hamiltonian function and further, we ... More
Symbolic powers of ideals of generic points in P^3May 02 2011B. Harbourne and C. Huneke conjectured that for any ideal $I$ of fat points in $P^N$ its $r$-th symbolic power $I^{(r)}$ should be contained in $M^{(N-1)r}I^r$, where $M$ denotes the homogeneous maximal ideal in the ring of coordinates of $P^N$. We show ... More
The fermionic observable in the Ising model and the inverse Kac-Ward operatorMar 12 2013Apr 30 2015We show that the critical Kac-Ward operator on isoradial graphs acts in a certain sense as the operator of s-holomorphicity, and we identify the fermionic observable for the spin Ising model as the inverse of this operator. This result is partially a ... More
Completeness of the isomorphism problem for separable C*-algebrasJun 05 2013Jul 13 2013We prove that the isomorphism problem for separable nuclear C*-algebras is complete in the class of orbit equivalence relations. In fact, already the isomorphism of simple, separable AI C*-algebras is a complete orbit equivalence relation. This means ... More
On Serre functor in the category of strict polynomial functorsMar 19 2016We introduce and study a Serre functor in the category ${\cal P}_d$ of strict polynomial functors over a field of positive characteristic. By using it we obtain the Poincar\'e duality formula for Ext--groups from [C3] in elementary way. We also show that ... More
Derived Kan extension for strict polynomial functorsJun 16 2011Nov 08 2014We investigate fundamental properties of adjoint functors to the precomposition functor in the category of strict polynomial functors.
Circle patterns and critical Ising modelsDec 23 2017A circle pattern is an embedding of a planar graph in which each face is inscribed in a circle. We define and prove magnetic criticality of a new family of Ising models on planar graphs whose dual is a circle pattern. Our construction includes as a special ... More
Square-free graphs are multiplicativeJan 18 2016Aug 23 2016A graph K is square-free if it contains no four-cycle as a subgraph. A graph K is multiplicative if GxH -> K implies G -> K or H -> K, for all graphs G,H. Here GxH is the tensor (or categorical) graph product and G -> K denotes the existence of a graph ... More
Long-Distance Entanglement of Soliton Spin Qubits in Gated NanowiresJan 08 2015We investigate numerically charge, spin, and entanglement dynamics of two electrons confined in a gated semiconductor nanowire. The electrostatic coupling between electrons in the nanowire and the charges in the metal gates leads to a self-trapping of ... More
Separable Hilbert space for loop quantizationMar 12 2014Sep 16 2014We discuss, within the simplified context provided by the polymeric harmonic oscillator, a construction leading to a separable Hilbert space that preserves some of the most important features of the spectrum of the Hamiltonian operator. This construction ... More
All electrically controlled quantum gates for single heavy hole spin qubitsApr 09 2013In this paper, several nanodevices which realize basic single heavy hole qubit operations are proposed and supported by time dependent self consistent Poisson-Schr\"{o}dinger calculations using a four band heavy hole-light hole model. In particular we ... More
Universe's memory and spontaneous coherence in loop quantum cosmologyJul 14 2016The quantum bounce a priori connects several (semi)classical epochs of Universe evolution, however determining if and how well the semiclassicality is preserved in this transition is highly nontrivial. We review the present state of knowledge in that ... More
Loop quantization of the Gowdy model with local rotational symmetryJun 18 2017We provide a full quantization of the vacuum Gowdy model with local rotational symmetry. We consider a redefinition of the constraints where the Hamiltonian Poisson-commutes with itself. We then apply the canonical quantization program of loop quantum ... More
The build-up of mass in UV-selected sub-L* galaxies at z~2Feb 09 2011Broadband spectral energy distribution (SED) fitting is used to study a deep sample of UV-selected sub-L* galaxies at z~2. They are found to be less dusty than L* galaxies, and to contribute more mass to the cosmic mass budget at this epoch than is inferred ... More
Phase transition free regions in the Ising model via the Kac-Ward operatorJun 10 2013May 17 2015We investigate the spectral radius and operator norm of the Kac-Ward transition matrix for the Ising model on a general planar graph. We then use the obtained results to identify regions in the complex plane where the free energy density limits are analytic ... More
Twist deformations of Newtonian Schwarzschild-(Anti-)de Sitter classical systemApr 26 2019In this article we provide three new twist-deformed Newtonian Schwarzschild-(Anti-)de Sitter models. They are defined on the Lie-algebraically as well as on the canonically noncommutative space-times respectively. Particularly we find the corresponding ... More
Regularity and non-emptyness of linear systems in $\mathbb P^n$Feb 07 2008The main goal of this paper is to present a new algorithm bounding the regularity and ``alpha'' (the lowest degree of existing hypersurface) of a linear system of hypersurfaces (in $\mathbb P^n$) passing through multiple points in general position. To ... More
Linear systems in P^3 with low degrees and low multiplicitiesOct 12 2008We prove that the linear system of hypersurfaces in P^3 of degree d, 14 <= d <= 40, with double, triple and quadruple points in general position are non-special. This solves the cases that have not been completed in a paper by E. Ballico and M.C. Brambilla. ... More
Extreme amenability of abelian $L_0$ groupsJan 03 2012We show that for any abelian topological group $G$ and arbitrary diffused submeasure $\mu$, every continuous action of $L_0(\mu,G)$ on a compact space has a fixed point. This generalizes earlier results of Herer and Christensen, Glasner, Furstenberg and ... More
Automatic continuity for isometry groupsDec 18 2013Jan 27 2014We present a general framework for automatic continuity results for groups of isometries of metric spaces. In particular, we prove automatic continuity property for the group of isometries of the Urysohn space and the Urysohn sphere, i.e. that any homomorphism ... More
Complexity of Ramsey null setsMar 31 2010We show that the set of codes for Ramsey positive analytic sets is $\mathbf{\Sigma}^1_2$-complete. This is a one projective-step higher analogue of the Hurewicz theorem saying that the set of codes for uncountable analytic sets is $\mathbf{\Sigma}^1_1$-complete. ... More
On spectra and affine strict polynomial functorsDec 31 2015We compare derived categories of the category of strict polynomial functors over a finite field and the category of ordinary endofunctors on the category of vector spaces. We introduce two intermediate categories: the category of $\infty$--affine strict ... More
Atomic decompositions for Hardy spaces related to Schrödinger operatorsSep 16 2014Let L_U = -Delta+U be a Schr\"odinger operator on R^d, where U\in L^1_{loc}(R^d) is a non-negative potential and d\geq 3. The Hardy space H^1(L_U) is defined in terms of the maximal function for the semigroup K_{t,U} = exp(-t L_U), namely H^1(L_U) = {f\in ... More
Riesz transform characterization of H^1 spaces associated with certain Laguerre expansionsFeb 17 2010Nov 26 2011For alpha>0 we consider the system l_k^{(alpha-1)/2}(x) of the Laguerre functions which are eigenfunctions of the differential operator Lf =-\frac{d^2}{dx^2}f-\frac{alpha}{x}\frac{d}{dx}f+x^2 f. We define an atomic Hardy space H^1_{at}(X), which is a ... More
Rabi-resonant behavior of periodically-driven correlated fermion systemsApr 11 2019Fermi-Hubbard system with a periodically-modulated interaction has been recently shown to resonantly absorb energy at series of drive frequencies. In the present work, with the help of static perturbation theory we argue that driving couples to Hubbard ... More
Alpha Cluster Model of Atomic NucleiJun 22 2015Mar 21 2016Description of a nuclear system in its ground state and at low excitations based on the equation of state (EoS) around normal density is presented. In the expansion of the EoS around the saturation point additional spin polarization terms are taken into ... More
Loop quantization of the Gowdy model with local rotational symmetrySep 30 2015We provide a full quantization of the vacuum Gowdy model with local rotational symmetry. We consider a redefinition of the constraints where the Hamiltonian Poisson-commutes with itself. We then apply of the canonical quantization program of loop quantum ... More
Elemental and tight monogamy relations in nonsignalling theoriesJul 24 2013May 26 2014Physical principles constrain the way nonlocal correlations can be distributed among distant parties. These constraints are usually expressed by monogamy relations that bound the amount of Bell inequality violation observed among a set of parties by the ... More
Sympathetic cooling of the Ba$^+$ ion by collisions with ultracold Rb atoms: theoretical prospectsAug 04 2010Jun 06 2011State-of-the-art {\em ab initio} techniques have been applied to compute the potential energy curves of the (BaRb)$^+$ molecular ion in the Born-Oppenheimer approximation. The long-range coefficients describing the electrostatic, induction, and dispersion ... More
Observations on interfacing loop quantum gravity with cosmologyNov 02 2014A simple idea of relating the LQG and LQC degrees of freedom is discussed in context of toroidal Bianchi I model. The idea is an expansion of the construction originally introduced by Ashtekar and Wilson-Ewing and relies on explicit averaging of certain ... More
On inverse powers of graphs and topological implications of Hedetniemi's conjectureDec 08 2017We consider a natural graph operation $\Omega_k$ that is a certain inverse (formally: the right adjoint) to taking the k-th power of a graph. We show that it preserves the topology (the $\mathbb{Z}_2$-homotopy type) of the box complex, a basic tool in ... More
A model of morphogen transport in the presence of glypicans IIINov 28 2014Apr 07 2015We analyse a stationary problem for the two dimensional model of morphogen transport introduced by Hufnagel et al. The model consists of one linear elliptic PDE posed on $(-1,1)\times(0,h)$ which is coupled via a nonlinear boundary condition with a nonlinear ... More
On inverse powers of graphs and topological implications of Hedetniemi's conjectureDec 08 2017May 13 2019We consider a natural graph operation $\Omega_k$ that is a certain inverse (formally: the right adjoint) to taking the k-th power of a graph. We show that it preserves the topology (the $\mathbb{Z}_2$-homotopy type) of the box complex, a basic tool in ... More
Galois theory for H-extensionsApr 29 2013We show that there exists a Galois correspondence between subalgebras of an H-comodule algebra A over a base ring R and generalised quotients of a Hopf algebra H if both A and H are flat Mittag--Leffler modules. We also provide new criteria for subalgebras ... More
Well-posedness and asymptotic behavior of a multidimensional model of morphogen transportDec 26 2011Morphogen transport is a biological process, occurring in the tissue of living organisms, which is a determining step in cell differentiation. We present rigorous analysis of a simple model of this process, which is a system coupling parabolic PDE with ... More
Quasi-homogeneous linear systems on P2 with base points of multiplicity 7, 8, 9, 10Apr 08 2008In the paper we prove Harbourne-Hirschowitz conjecture for quasi-homogeneous linear systems on $\mathbb P^2$ for $m=7$, 8, 9, 10, i.e. systems of curves of given degree passing through points in general position with multiplicities at least $m,...,m,m_0$, ... More
Casimir effect for tachyonic fieldsJul 04 2003Aug 29 2003In this paper we examine Casimir effect in the case of tachyonic field, which is connected with particles with negative four-momentum square. We consider here only the case of one dimensional, scalar field. In order to describe tachyonic field, we use ... More
Algebraic approximation of analytic sets and mappingsDec 19 2007Let {X_n} be a sequence of analytic sets converging to some analytic set X in the sense of holomorphic chains. We introduce a condition which implies that every irreducible component of X is the limit of a sequence of irreducible components of the sets ... More
The relation between the quantum games, communication complexity problems and Bell inequalitiesOct 22 2007We study the relation between the quantum games, communication complexity problems and Bell inequalities. In particular we are interested in answering the question whether for every element of one of these groups there is a corresponding element in the ... More
Casimir effect in external magnetic fieldApr 13 2005Dec 19 2005In this paper we examine the Casimir effect for charged fields in presence of external magnetic field. We consider scalar field (connected with spinless particles) and the Dirac field (connected with 1/2-spin particles). In both cases we describe quantum ... More
The Ultraviolet-Far Infrared Energy Budget of the Gravitationally Lensed Lyman Break Galaxy MS1512-cB58Feb 12 2001A 2-hour service-mode SCUBA observation of the gravitationally-lensed Lyman break galaxy MS1512-cB58 resulted in a 3 sigma upper limit of 3.9 mJy at 850um. A comparison of this upper limit with values expected from rest-UV/optical measurements of extiction ... More
Remarks on normal basesOct 13 1997We prove that any Galois extension of commutative rings with normal basis and abelian Galois group of odd order has a self dual normal basis. Also we show that if S/R is an unramified extension of number rings with Galois group of odd order and $R$ is ... More
Quantum Information Processing with Continuous Variables and Atomic EnsemblesFeb 09 2011This thesis presents three different results in quantum information theory. The first result addresses the theoretical foundations of quantum metrology. The Heisenberg limit considered as the ultimate limit in quantum metrology sets a lower bound on how ... More
Weak solutions to the quaternionic Monge-Ampère equationJul 06 2018We solve the Dirichlet problem for the quaternionic Monge-Amp\`ere equation with a continuous boundary data and the right hand side in $L^p$ for $p>2$. This is the optimal bound on $p$. We prove also that the local integrability exponent of quaternionic ... More
Photoelectric effect for twist-deformed space-timeMay 18 2016In this article, we investigate the impact of twisted space-time on the photoelectric effect, i.e., we derive the $\theta$-deformed threshold frequency. In such a way we indicate that the space-time noncommutativity strongly enhances the photoelectric ... More
The Kadison-Singer ProblemFeb 15 2017Feb 01 2018We give self-contained presentation of results related to the Kadison-Singer problem, which was recently solved by Marcus, Spielman, and Srivastava. This problem connects with unusually large number of areas including: operator algebras (pure states), ... More
Black-body radiation for twist-deformed space-timeDec 30 2015In this article we formally investigate the impact of twisted space-time on black-body radiation phenomena, i.e. we derive the $\theta$-deformed Planck distribution function as well as we perform its numerical integration to the $\theta$-deformed total ... More
Model of hydrogen atom for twisted acceleration-enlarged Newton-Hooke space-timesDec 09 2013We define the model of hydrogen atom for twist-deformed acceleration-enlarged Newton-Hooke space-time. Further, using time-dependent perturbation theory, we find in first step of iteration procedure the solution of corresponding Schroedinger equation ... More
Classical torus conformal block, N=2* twisted superpotential and the accessory parameter of Lame equationSep 29 2013Apr 02 2014In this work the correspondence between the semiclassical limit of the DOZZ quantum Liouville theory on the torus and the Nekrasov-Shatashvili limit of the N=2* (Omega-deformed) U(2) super-Yang-Mills theory is used to propose new formulae for the accessory ... More
t-t'-J-U model in mean-field approximation: Coexistence of superconductivity and antiferromagnetismNov 07 2014We discuss the $t$-$J$-$U$ model in the mean-field approximation. The role of spin-exchange coupling $J$ and the second nearest hopping $t'$ are examined in the context of the coexistence of superconductivity (SC) and antiferromagnetism (AF). Stability ... More
Homomorphism reconfiguration via homotopyAug 12 2014Mar 24 2017We consider the following problem for a fixed graph H: given a graph G and two H-colorings of G, i.e. homomorphisms from G to H, can one be transformed (reconfigured) into the other by changing one color at a time, maintaining an H-coloring throughout. ... More
Classification of automatic software build methodsMay 21 2013The process of creating working software from source code and other components (like libraries, database files, etc.) is called "software build". Apart from linking and compiling, it can include other steps like automated testing, static code analysis, ... More
Searches for LFV and LNV Decays at LHCbJan 10 2013The paper presents the latest progress on the searches for Lepton Number Violating (LNV) B Meson decays, the Lepton Flavour Violating (LFV) decay $\Ptau^- \to \Pmu^-\Pmu^-\Pmu^+$, and the Lepton and Baryon Number Violating (LNV and BNV) decays $\Ptau^- ... More
Quantum mechanics of many particles defined on twisted N-enlarged Newton-Hooke space-timesApr 25 2013We provide the quantum mechanics of many particles moving in twisted N-enlarged Newton-Hooke space-time. In particular, we consider the example of such noncommutative system - the set of M particles moving in Coulomb field of external point-like source ... More
Twist deformation of doubly enlarged Newton-Hooke Hopf algebraApr 27 2012We provide fifteen twist-deformed doubly enlarged Newton-Hooke quantum space-times. In $\tau$ approaching infinity limit the twisted doubly enlarged Galilei spaces are obtained as well.
Twisted acceleration-enlarged Newton-Hooke space-times and breaking classical symmetry phenomenaJan 25 2012We find the subgroup of classical acceleration-enlarged Newton-Hooke Hopf algebra which acts covariantly on the twisted acceleration-enlarged Newton-Hooke space-times. The case of classical acceleration-enlarged Galilei quantum group is considered as ... More
RBO Protocol: Broadcasting Huge Databases for Tiny ReceiversAug 25 2011We propose a protocol (called RBO) for broadcasting long streams of single-packet messages over radio channel for tiny, battery powered, receivers. The messages are labeled by the keys from some linearly ordered set. The sender repeatedly broadcasts a ... More
Acrylic purification and coatingsSep 21 2012Radon (Rn) and its decay daughters are a well-known source of background in direct WIMP detection experiments, as either a Rn decay daughter or an alpha particle emitted from a thin inner surface layer of a detector could produce a WIMP-like signal. Different ... More
Saturation of uncertainty relations for twisted acceleration-enlarged Newton-Hooke space-timesSep 07 2011Using Fock representation we construct states saturating uncertainty relations for twist-deformed acceleration-enlarged Newton-Hooke space-times.
13/9-approximation for Graphic TSPAug 04 2011Oct 04 2011The Travelling Salesman Problem is one the most fundamental and most studied problems in approximation algorithms. For more than 30 years, the best algorithm known for general metrics has been Christofides's algorithm with approximation factor of 3/2, ... More
Decoherence through Spin Chains: Toy ModelAug 22 2011Aug 29 2011The description of the dynamics of closed quantum systems, governed by the Schroedinger equation at first sight seems incompatible with the Lindblad equation describing open ones. By analyzing closed dynamics of a spin-1/2 chain we reconstruct exponential ... More
Poincaré duality for Ext-groups between strict polynomial fucnctorsNov 09 2014We study relation between left and right adjoint functors to the precomposition functor. As a cosnequence we obtain various dualities in the Ext-groups in the category of strict polynomial functors.
Low-dimensional quantum systemsOct 17 2018We study low-dimensional quantum systems with analytical and computational methods. Firstly, the one-dimensional extended $t$-$V$ model of fermions with interactions of a finite range is investigated. The model exhibits a phase transition between liquid ... More
On extremal positive maps acting between type I factorsDec 12 2008Dec 20 2008The paper is devoted to the problem of classification of extremal positive maps acting between $B(K)$ and $B(H)$ where $K$ and $H$ are Hilbert spaces. It is shown that every positive map with the property that $\rank \phi(P)\leq 1$ for any one-dimensional ... More
Rank properties of exposed positive mapsMar 17 2011May 10 2012Let $\cK$ and $\cH$ be finite dimensional Hilbert spaces and let $\fP$ denote the cone of all positive linear maps acting from $\fB(\cK)$ into $\fB(\cH)$. We show that each map of the form $\phi(X)=AXA^*$ or $\phi(X)=AX^TA^*$ is an exposed point of $\fP$. ... More
Communication Complexity Reduction from Globally Uncorrelated StatesDec 11 2012Bell inequality violating entangled states are the working horse for many potential quantum information processing applications, including secret sharing, cryptographic key distribution and communication complexity reduction in distributed computing. ... More
SEDfit: Software for Spectral Energy Distribution Fitting of Photometric DataOct 01 2012This paper describes SEDfit, the earliest --- but continually upgraded --- software package for spectral energy distribution fitting (SED fitting) of high-redshift photometric data, and the only one to properly treat non-detections. The principles of ... More
Numerical investigations of the Schwinger model and selected quantum spin modelsMar 03 2013Numerical investigations of the XY model, the Heisenberg model and the J-J' Heisenberg model are conducted, using the exact diagonalisation, the numerical renormalisation and the density matrix renormalisation group approach. The low-lying energy levels ... More
N-enlarged Galilei Hopf algebra and its twist deformationsMay 02 2012The N-enlarged Galilei Hopf algebra is constructed. Its twist deformations are considered and the corresponding twisted space-times are derived.
Landau energy spectrum and quantum oscillator model for twisted N-enlarged Newton-Hooke space-timeDec 18 2014We derive the energy levels for oscillator model defined on the twisted N-enlarged Newton-Hooke space-time, i.e., we find time-dependent eigenvalues and corresponding time-dependent eigenstates. We also demonstrate that for a particular choice of deformation ... More
Reconfiguration in bounded bandwidth and treedepthMay 05 2014We show that several reconfiguration problems known to be PSPACE-complete remain so even when limited to graphs of bounded bandwidth. The essential step is noticing the similarity to very limited string rewriting systems, whose ability to directly simulate ... More
Sitnikov problem as a source of jetsAug 26 2011Sitnikov problem, consisting two close binaries and a third small body is considered, leading to a rapid ejection of the small body from the binaries. This mechanism is proposed as an explanation of jets in many astrophysical systems. Choosing appropriate ... More