@phdthesis{Mueller2008,
  author    = {M{\"u}ller, Melanie J. I.},
  title     = {Bidirectional transport by molecular motors},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-18715},
  school      = {Universit{\"a}t Potsdam},
  year      = {2008},
  abstract  = {In biological cells, the long-range intracellular traffic is powered by molecular motors which transport various cargos along microtubule filaments. The microtubules possess an intrinsic direction, having a 'plus' and a 'minus' end. Some molecular motors such as cytoplasmic dynein walk to the minus end, while others such as conventional kinesin walk to the plus end. Cells typically have an isopolar microtubule network. This is most pronounced in neuronal axons or fungal hyphae. In these long and thin tubular protrusions, the microtubules are arranged parallel to the tube axis with the minus ends pointing to the cell body and the plus ends pointing to the tip. In such a tubular compartment, transport by only one motor type leads to 'motor traffic jams'. Kinesin-driven cargos accumulate at the tip, while dynein-driven cargos accumulate near the cell body. We identify the relevant length scales and characterize the jamming behaviour in these tube geometries by using both Monte Carlo simulations and analytical calculations. A possible solution to this jamming problem is to transport cargos with a team of plus and a team of minus motors simultaneously, so that they can travel bidirectionally, as observed in cells. The presumably simplest mechanism for such bidirectional transport is provided by a 'tug-of-war' between the two motor teams which is governed by mechanical motor interactions only. We develop a stochastic tug-of-war model and study it with numerical and analytical calculations. We find a surprisingly complex cooperative motility behaviour. We compare our results to the available experimental data, which we reproduce qualitatively and quantitatively.},
  language  = {en}
}
@phdthesis{Loeffler2005,
  author    = {L{\"o}ffler, Frank},
  title     = {Numerical simulations of neutron star - black hole mergers},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7743},
  school      = {Universit{\"a}t Potsdam},
  year      = {2005},
  abstract  = {Collisions of black holes and neutron stars, named mixed binaries in the following, are interesting because of at least two reasons. Firstly, it is expected that they emit a large amount of energy as gravitational waves, which could be measured by new detectors. The form of those waves is expected to carry information about the internal structure of such systems. Secondly, collisions of such objects are the prime suspects of short gamma ray bursts. The exact mechanism for the energy emission is unknown so far. In the past, Newtonian theory of gravitation and modifications to it were often used for numerical simulations of collisions of mixed binary systems. However, near to such objects, the gravitational forces are so strong, that the use of General Relativity is necessary for accurate predictions. There are a lot of problems in general relativistic simulations. However, systems of two neutron stars and systems of two black holes have been studies extensively in the past and a lot of those problems have been solved. One of the remaining problems so far has been the use of hydrodynamic on excision boundaries. Inside excision regions, no evolution is carried out. Such regions are often used inside black holes to circumvent instabilities of the numerical methods near the singularity. Methods to handle hydrodynamics at such boundaries have been described and tests are shown in this work. One important test and the first application of those methods has been the simulation of a collapsing neutron star to a black hole. The success of these simulations and in particular the performance of the excision methods was an important step towards simulations of mixed binaries. Initial data are necessary for every numerical simulation. However, the creation of such initial data for general relativistic situations is in general very complicated. In this work it is shown how to obtain initial data for mixed binary systems using an already existing method for initial data of two black holes. These initial data have been used for evolutions of such systems and problems encountered are discussed in this work. One of the problems are instabilities due to different methods, which could be solved by dissipation of appropriate strength. Another problem is the expected drift of the black hole towards the neutron star. It is shown, that this can be solved by using special gauge conditions, which prevent the black hole from moving on the computational grid. The methods and simulations shown in this work are only the starting step for a much more detailed study of mixed binary system. Better methods, models and simulations with higher resolution and even better gauge conditions will be focus of future work. It is expected that such detailed studies can give information about the emitted gravitational waves, which is important in view of the newly built gravitational wave detectors. In addition, these simulations could give insight into the processes responsible for short gamma ray bursts.},
  subject      = {Relativistische Astrophysik},
  language  = {en}
}
@phdthesis{Prevot2006,
  author    = {Prevot, Michelle Elizabeth},
  title     = {Introduction of a thermo-sensitive non-polar species into polyelectrolyte multilayer capsules for drug delivery},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7785},
  school      = {Universit{\"a}t Potsdam},
  year      = {2006},
  abstract  = {The layer-by-layer assembly (LBL) of polyelectrolytes has been extensively studied for the preparation of ultrathin films due to the versatility of the build-up process. The control of the permeability of these layers is particularly important as there are potential drug delivery applications. Multilayered polyelectrolyte microcapsules are also of great interest due to their possible use as microcontainers. This work will present two methods that can be used as employable drug delivery systems, both of which can encapsulate an active molecule and tune the release properties of the active species. Poly-(N-isopropyl acrylamide), (PNIPAM) is known to be a thermo-sensitive polymer that has a Lower Critical Solution Temperature (LCST) around 32oC; above this temperature PNIPAM is insoluble in water and collapses. It is also known that with the addition of salt, the LCST decreases. This work shows Differential Scanning Calorimetry (DSC) and Confocal Laser Scanning Microscopy (CLSM) evidence that the LCST of the PNIPAM can be tuned with salt type and concentration. Microcapsules were used to encapsulate this thermo-sensitive polymer, resulting in a reversible and tunable stimuli- responsive system. The encapsulation of the PNIPAM inside of the capsule was proven with Raman spectroscopy, DSC (bulk LCST measurements), AFM (thickness change), SEM (morphology change) and CLSM (in situ LCST measurement inside of the capsules). The exploitation of the capsules as a microcontainer is advantageous not only because of the protection the capsules give to the active molecules, but also because it facilitates easier transport. The second system investigated demonstrates the ability to reduce the permeability of polyelectrolyte multilayer films by the addition of charged wax particles. The incorporation of this hydrophobic coating leads to a reduced water sensitivity particularly after heating, which melts the wax, forming a barrier layer. This conclusion was proven with Neutron Reflectivity by showing the decreased presence of D2O in planar polyelectrolyte films after annealing creating a barrier layer. The permeability of capsules could also be decreased by the addition of a wax layer. This was proved by the increase in recovery time measured by Florescence Recovery After Photobleaching, (FRAP) measurements. In general two advanced methods, potentially suitable for drug delivery systems, have been proposed. In both cases, if biocompatible elements are used to fabricate the capsule wall, these systems provide a stable method of encapsulating active molecules. Stable encapsulation coupled with the ability to tune the wall thickness gives the ability to control the release profile of the molecule of interest.},
  subject      = {Mikrokapsel},
  language  = {en}
}
@phdthesis{Miteva2007,
  author    = {Miteva, Rositsa Stoycheva},
  title     = {Electron acceleration at localized wave structures in the solar corona},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-14775},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {Our dynamic Sun manifests its activity by different phenomena: from the 11-year cyclic sunspot pattern to the unpredictable and violent explosions in the case of solar flares. During flares, a huge amount of the stored magnetic energy is suddenly released and a substantial part of this energy is carried by the energetic electrons, considered to be the source of the nonthermal radio and X-ray radiation. One of the most important and still open question in solar physics is how the electrons are accelerated up to high energies within (the observed in the radio emission) short time scales. Because the acceleration site is extremely small in spatial extent as well (compared to the solar radius), the electron acceleration is regarded as a local process. The search for localized wave structures in the solar corona that are able to accelerate electrons together with the theoretical and numerical description of the conditions and requirements for this process, is the aim of the dissertation. Two models of electron acceleration in the solar corona are proposed in the dissertation: I. Electron acceleration due to the solar jet interaction with the background coronal plasma (the jet--plasma interaction) A jet is formed when the newly reconnected and highly curved magnetic field lines are relaxed by shooting plasma away from the reconnection site. Such jets, as observed in soft X-rays with the Yohkoh satellite, are spatially and temporally associated with beams of nonthermal electrons (in terms of the so-called type III metric radio bursts) propagating through the corona. A model that attempts to give an explanation for such observational facts is developed here. Initially, the interaction of such jets with the background plasma leads to an (ion-acoustic) instability associated with growing of electrostatic fluctuations in time for certain range of the jet initial velocity. During this process, any test electron that happen to feel this electrostatic wave field is drawn to co-move with the wave, gaining energy from it. When the jet speed has a value greater or lower than the one, required by the instability range, such wave excitation cannot be sustained and the process of electron energization (acceleration and/or heating) ceases. Hence, the electrons can propagate further in the corona and be detected as type III radio burst, for example. II. Electron acceleration due to attached whistler waves in the upstream region of coronal shocks (the electron--whistler--shock interaction) Coronal shocks are also able to accelerate electrons, as observed by the so-called type II metric radio bursts (the radio signature of a shock wave in the corona). From in-situ observations in space, e.g., at shocks related to co-rotating interaction regions, it is known that nonthermal electrons are produced preferably at shocks with attached whistler wave packets in their upstream regions. Motivated by these observations and assuming that the physical processes at shocks are the same in the corona as in the interplanetary medium, a new model of electron acceleration at coronal shocks is presented in the dissertation, where the electrons are accelerated by their interaction with such whistlers. The protons inflowing toward the shock are reflected there by nearly conserving their magnetic moment, so that they get a substantial velocity gain in the case of a quasi-perpendicular shock geometry, i.e, the angle between the shock normal and the upstream magnetic field is in the range 50--80 degrees. The so-accelerated protons are able to excite whistler waves in a certain frequency range in the upstream region. When these whistlers (comprising the localized wave structure in this case) are formed, only the incoming electrons are now able to interact resonantly with them. But only a part of these electrons fulfill the the electron--whistler wave resonance condition. Due to such resonant interaction (i.e., of these electrons with the whistlers), the electrons are accelerated in the electric and magnetic wave field within just several whistler periods. While gaining energy from the whistler wave field, the electrons reach the shock front and, subsequently, a major part of them are reflected back into the upstream region, since the shock accompanied with a jump of the magnetic field acts as a magnetic mirror. Co-moving with the whistlers now, the reflected electrons are out of resonance and hence can propagate undisturbed into the far upstream region, where they are detected in terms of type II metric radio bursts. In summary, the kinetic energy of protons is transfered into electrons by the action of localized wave structures in both cases, i.e., at jets outflowing from the magnetic reconnection site and at shock waves in the corona.},
  language  = {en}
}
@phdthesis{Kellermann2011,
  author    = {Kellermann, Thorsten},
  title     = {Accurate numerical relativity simulations of non-vacuumspace-times in two dimensions and applications to critical collapse},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59578},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {This Thesis puts its focus on the physics of neutron stars and its description with methods of numerical relativity. In the first step, a new numerical framework the Whisky2D code will be developed, which solves the relativistic equations of hydrodynamics in axisymmetry. Therefore we consider an improved formulation of the conserved form of these equations. The second part will use the new code to investigate the critical behaviour of two colliding neutron stars. Considering the analogy to phase transitions in statistical physics, we will investigate the evolution of the entropy of the neutron stars during the whole process. A better understanding of the evolution of thermodynamical quantities, like the entropy in critical process, should provide deeper understanding of thermodynamics in relativity. More specifically, we have written the Whisky2D code, which solves the general-relativistic hydrodynamics equations in a flux-conservative form and in cylindrical coordinates. This of course brings in 1/r singular terms, where r is the radial cylindrical coordinate, which must be dealt with appropriately. In the above-referenced works, the flux operator is expanded and the 1/r terms, not containing derivatives, are moved to the right-hand-side of the equation (the source term), so that the left hand side assumes a form identical to the one of the three-dimensional (3D) Cartesian formulation. We call this the standard formulation. Another possibility is not to split the flux operator and to redefine the conserved variables, via a multiplication by r. We call this the new formulation. The new equations are solved with the same methods as in the Cartesian case. From a mathematical point of view, one would not expect differences between the two ways of writing the differential operator, but, of course, a difference is present at the numerical level. Our tests show that the new formulation yields results with a global truncation error which is one or more orders of magnitude smaller than those of alternative and commonly used formulations. The second part of the Thesis uses the new code for investigations of critical phenomena in general relativity. In particular, we consider the head-on-collision of two neutron stars in a region of the parameter space where two final states a new stable neutron star or a black hole, lay close to each other. In 1993, Choptuik considered one-parameter families of solutions, S[P], of the Einstein-Klein-Gordon equations for a massless scalar field in spherical symmetry, such that for every P > P⋆, S[P] contains a black hole and for every P < P⋆, S[P] is a solution not containing singularities. He studied numerically the behavior of S[P] as P → P⋆ and found that the critical solution, S[P⋆], is universal, in the sense that it is approached by all nearly-critical solutions regardless of the particular family of initial data considered. All these phenomena have the common property that, as P approaches P⋆, S[P] approaches a universal solution S[P⋆] and that all the physical quantities of S[P] depend only on |P - P⋆|. The first study of critical phenomena concerning the head-on collision of NSs was carried out by Jin and Suen in 2007. In particular, they considered a series of families of equal-mass NSs, modeled with an ideal-gas EOS, boosted towards each other and varied the mass of the stars, their separation, velocity and the polytropic index in the EOS. In this way they could observe a critical phenomenon of type I near the threshold of black-hole formation, with the putative solution being a nonlinearly oscillating star. In a successive work, they performed similar simulations but considering the head-on collision of Gaussian distributions of matter. Also in this case they found the appearance of type-I critical behaviour, but also performed a perturbative analysis of the initial distributions of matter and of the merged object. Because of the considerable difference found in the eigenfrequencies in the two cases, they concluded that the critical solution does not represent a system near equilibrium and in particular not a perturbed Tolmann-Oppenheimer-Volkoff (TOV) solution. In this Thesis we study the dynamics of the head-on collision of two equal-mass NSs using a setup which is as similar as possible to the one considered above. While we confirm that the merged object exhibits a type-I critical behaviour, we also argue against the conclusion that the critical solution cannot be described in terms of equilibrium solution. Indeed, we show that, in analogy with what is found in, the critical solution is effectively a perturbed unstable solution of the TOV equations. Our analysis also considers fine-structure of the scaling relation of type-I critical phenomena and we show that it exhibits oscillations in a similar way to the one studied in the context of scalar-field critical collapse.},
  language  = {en}
}
@phdthesis{Berger2012,
  author    = {Berger, Florian},
  title     = {Different modes of cooperative transport by molecular motors},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60319},
  school      = {Universit{\"a}t Potsdam},
  year      = {2012},
  abstract  = {Cargo transport by molecular motors is ubiquitous in all eukaryotic cells and is typically driven cooperatively by several molecular motors, which may belong to one or several motor species like kinesin, dynein or myosin. These motor proteins transport cargos such as RNAs, protein complexes or organelles along filaments, from which they unbind after a finite run length. Understanding how these motors interact and how their movements are coordinated and regulated is a central and challenging problem in studies of intracellular transport. In this thesis, we describe a general theoretical framework for the analysis of such transport processes, which enables us to explain the behavior of intracellular cargos based on the transport properties of individual motors and their interactions. Motivated by recent in vitro experiments, we address two different modes of transport: unidirectional transport by two identical motors and cooperative transport by actively walking and passively diffusing motors. The case of cargo transport by two identical motors involves an elastic coupling between the motors that can reduce the motors' velocity and/or the binding time to the filament. We show that this elastic coupling leads, in general, to four distinct transport regimes. In addition to a weak coupling regime, kinesin and dynein motors are found to exhibit a strong coupling and an enhanced unbinding regime, whereas myosin motors are predicted to attain a reduced velocity regime. All of these regimes, which we derive both by analytical calculations and by general time scale arguments, can be explored experimentally by varying the elastic coupling strength. In addition, using the time scale arguments, we explain why previous studies came to different conclusions about the effect and relevance of motor-motor interference. In this way, our theory provides a general and unifying framework for understanding the dynamical behavior of two elastically coupled molecular motors. The second mode of transport studied in this thesis is cargo transport by actively pulling and passively diffusing motors. Although these passive motors do not participate in active transport, they strongly enhance the overall cargo run length. When an active motor unbinds, the cargo is still tethered to the filament by the passive motors, giving the unbound motor the chance to rebind and continue its active walk. We develop a stochastic description for such cooperative behavior and explicitly derive the enhanced run length for a cargo transported by one actively pulling and one passively diffusing motor. We generalize our description to the case of several pulling and diffusing motors and find an exponential increase of the run length with the number of involved motors.},
  language  = {en}
}
@phdthesis{Bierbaum2011,
  author    = {Bierbaum, Veronika},
  title     = {Chemomechanical coupling and motor cycles of the molecular motor myosin V},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53614},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {In the living cell, the organization of the complex internal structure relies to a large extent on molecular motors. Molecular motors are proteins that are able to convert chemical energy from the hydrolysis of adenosine triphosphate (ATP) into mechanical work. Being about 10 to 100 nanometers in size, the molecules act on a length scale, for which thermal collisions have a considerable impact onto their motion. In this way, they constitute paradigmatic examples of thermodynamic machines out of equilibrium. This study develops a theoretical description for the energy conversion by the molecular motor myosin V, using many different aspects of theoretical physics. Myosin V has been studied extensively in both bulk and single molecule experiments. Its stepping velocity has been characterized as a function of external control parameters such as nucleotide concentration and applied forces. In addition, numerous kinetic rates involved in the enzymatic reaction of the molecule have been determined. For forces that exceed the stall force of the motor, myosin V exhibits a 'ratcheting' behaviour: For loads in the direction of forward stepping, the velocity depends on the concentration of ATP, while for backward loads there is no such influence. Based on the chemical states of the motor, we construct a general network theory that incorporates experimental observations about the stepping behaviour of myosin V. The motor's motion is captured through the network description supplemented by a Markov process to describe the motor dynamics. This approach has the advantage of directly addressing the chemical kinetics of the molecule, and treating the mechanical and chemical processes on equal grounds. We utilize constraints arising from nonequilibrium thermodynamics to determine motor parameters and demonstrate that the motor behaviour is governed by several chemomechanical motor cycles. In addition, we investigate the functional dependence of stepping rates on force by deducing the motor's response to external loads via an appropriate Fokker-Planck equation. For substall forces, the dominant pathway of the motor network is profoundly different from the one for superstall forces, which leads to a stepping behaviour that is in agreement with the experimental observations. The extension of our analysis to Markov processes with absorbing boundaries allows for the calculation of the motor's dwell time distributions. These reveal aspects of the coordination of the motor's heads and contain direct information about the backsteps of the motor. Our theory provides a unified description for the myosin V motor as studied in single motor experiments.},
  language  = {en}
}
@phdthesis{Rust2007,
  author    = {Rust, Henning},
  title     = {Detection of long-range dependence : applications in climatology and hydrology},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-13347},
  school      = {Universit{\"a}t Potsdam},
  year      = {2007},
  abstract  = {It is desirable to reduce the potential threats that result from the variability of nature, such as droughts or heat waves that lead to food shortage, or the other extreme, floods that lead to severe damage. To prevent such catastrophic events, it is necessary to understand, and to be capable of characterising, nature's variability. Typically one aims to describe the underlying dynamics of geophysical records with differential equations. There are, however, situations where this does not support the objectives, or is not feasible, e.g., when little is known about the system, or it is too complex for the model parameters to be identified. In such situations it is beneficial to regard certain influences as random, and describe them with stochastic processes. In this thesis I focus on such a description with linear stochastic processes of the FARIMA type and concentrate on the detection of long-range dependence. Long-range dependent processes show an algebraic (i.e. slow) decay of the autocorrelation function. Detection of the latter is important with respect to, e.g. trend tests and uncertainty analysis. Aiming to provide a reliable and powerful strategy for the detection of long-range dependence, I suggest a way of addressing the problem which is somewhat different from standard approaches. Commonly used methods are based either on investigating the asymptotic behaviour (e.g., log-periodogram regression), or on finding a suitable potentially long-range dependent model (e.g., FARIMA[p,d,q]) and test the fractional difference parameter d for compatibility with zero. Here, I suggest to rephrase the problem as a model selection task, i.e.comparing the most suitable long-range dependent and the most suitable short-range dependent model. Approaching the task this way requires a) a suitable class of long-range and short-range dependent models along with suitable means for parameter estimation and b) a reliable model selection strategy, capable of discriminating also non-nested models. With the flexible FARIMA model class together with the Whittle estimator the first requirement is fulfilled. Standard model selection strategies, e.g., the likelihood-ratio test, is for a comparison of non-nested models frequently not powerful enough. Thus, I suggest to extend this strategy with a simulation based model selection approach suitable for such a direct comparison. The approach follows the procedure of a statistical test, with the likelihood-ratio as the test statistic. Its distribution is obtained via simulations using the two models under consideration. For two simple models and different parameter values, I investigate the reliability of p-value and power estimates obtained from the simulated distributions. The result turned out to be dependent on the model parameters. However, in many cases the estimates allow an adequate model selection to be established. An important feature of this approach is that it immediately reveals the ability or inability to discriminate between the two models under consideration. Two applications, a trend detection problem in temperature records and an uncertainty analysis for flood return level estimation, accentuate the importance of having reliable methods at hand for the detection of long-range dependence. In the case of trend detection, falsely concluding long-range dependence implies an underestimation of a trend and possibly leads to a delay of measures needed to take in order to counteract the trend. Ignoring long-range dependence, although present, leads to an underestimation of confidence intervals and thus to an unjustified belief in safety, as it is the case for the return level uncertainty analysis. A reliable detection of long-range dependence is thus highly relevant in practical applications. Examples related to extreme value analysis are not limited to hydrological applications. The increased uncertainty of return level estimates is a potentially problem for all records from autocorrelated processes, an interesting examples in this respect is the assessment of the maximum strength of wind gusts, which is important for designing wind turbines. The detection of long-range dependence is also a relevant problem in the exploration of financial market volatility. With rephrasing the detection problem as a model selection task and suggesting refined methods for model comparison, this thesis contributes to the discussion on and development of methods for the detection of long-range dependence.},
  language  = {en}
}
@article{TeichmannLewandowskiAlemani2022,
  author    = {Teichmann, Erik and Lewandowski, Heather J. and Alemani, Micol},
  title     = {Investigating students' views of experimental physics in German laboratory classes},
  series = {Physical Review Physics Education Research},
  volume    = {18},
  journal   = {Physical Review Physics Education Research},
  edition   = {1},
  publisher = {APS},
  address   = {College Park, Maryland, United States},
  issn      = {1554-9178},
  doi       = {10.1103/PhysRevPhysEducRes.18.010135},
  pages     = {010135-1 -- 010135-17},
  year      = {2022},
  abstract  = {There is a large variety of goals instructors have for laboratory courses, with different courses focusing on different subsets of goals. An often implicit, but crucial, goal is to develop students' attitudes, views, and expectations about experimental physics to align with practicing experimental physicists. The assessment of laboratory courses upon this one dimension of learning has been intensively studied in U.S. institutions using the Colorado Learning Attitudes about Science Survey for Experimental Physics (E-CLASS). However, there is no such an instrument available to use in Germany, and the influence of laboratory courses on students views about the nature of experimental physics is still unexplored at German-speaking institutions. Motivated by the lack of an assessment tool to investigate this goal in laboratory courses at German-speaking institutions, we present a translated version of the E-CLASS adapted to the context at German-speaking institutions. We call the German version of the E-CLASS, the GE-CLASS. We describe the translation process and the creation of an automated web-based system for instructors to assess their laboratory courses. We also present first results using GE-CLASS obtained at the University of Potsdam. A first comparison between E-CLASS and GE-CLASS results shows clear differences between University of Potsdam and U.S. students' views and beliefs about experimental physics.},
  language  = {en}
}
@article{SarabadaniMetzlerAlaNissila2022,
  author    = {Sarabadani, Jalal and Metzler, Ralf and Ala-Nissila, Tapio},
  title     = {Driven polymer translocation into a channel: Isoflux tension propagation theory and Langevin dynamics simulations},
  series = {Physical Review Research},
  volume    = {4},
  journal   = {Physical Review Research},
  edition   = {3},
  publisher = {American Physical Society},
  address   = {College Park, Maryland, USA},
  issn      = {2643-1564},
  doi       = {10.1103/PhysRevResearch.4.033003},
  pages     = {033003-1 -- 033003-14},
  year      = {2022},
  abstract  = {Isoflux tension propagation (IFTP) theory and Langevin dynamics (LD) simulations are employed to study the dynamics of channel-driven polymer translocation in which a polymer translocates into a narrow channel and the monomers in the channel experience a driving force fc. In the high driving force limit, regardless of the channel width, IFTP theory predicts τ ∝ f βc for the translocation time, where β = -1 is the force scaling exponent. Moreover, LD data show that for a very narrow channel fitting only a single file of monomers, the entropic force due to the subchain inside the channel does not play a significant role in the translocation dynamics and the force exponent β = -1 regardless of the force magnitude. As the channel width increases the number of possible spatial configurations of the subchain inside the channel becomes significant and the resulting entropic force causes the force exponent to drop below unity.},
  language  = {en}
}