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Journals in Physics

Physics titles offer comprehensive research and advancements across the fundamental and applied areas of physical science. From quantum mechanics and particle physics to astrophysics and materials science, these titles drive innovation and deepen understanding of the principles governing the universe. Essential for researchers, educators, and students, this collection supports scientific progress and practical applications across a diverse range of physics disciplines.

  • Journal of Magnetism and Magnetic Materials

    • ISSN: 0304-8853
    The Journal of Magnetism and Magnetic Materials provides an important forum for the disclosure and discussion of original contributions covering the whole spectrum of topics, from basic magnetism to the technology and applications of magnetic materials. The journal encourages greater interaction between the basic and applied sub-disciplines of magnetism with comprehensive review articles, in addition to full-length contributions. In addition, other categories of contributions are welcomed, including Critical Focused issues, Current Perspectives, and Outreach to the General Public.Main Categories: Full-length articles: Technically original research documents that report results of value to the communities that comprise the journal audience. The link between chemical, structural and microstructural properties on the one hand and magnetic properties on the other hand are encouraged.In addition to general topics covering all areas of magnetism and magnetic materials, the full-length articles also include three sub-sections, focusing on Nanomagnetism, Spintronics and Applications. The sub-section on Nanomagnetism contains articles on magnetic nanoparticles, nanowires, thin films, 2D materials and other nanoscale magnetic materials and their applications. The sub-section on Spintronics contains articles on magnetoresistance, magnetoimpedance, magneto-optical phenomena, Micro-Electro-Mechan... Systems (MEMS), and other topics related to spin current control and magneto-transport phenomena. The sub-section on Applications display papers that focus on applications of magnetic materials. The applications need to show a connection to magnetism.Review articles: Review articles organize, clarify, and summarize existing major works in the areas covered by the Journal and provide comprehensive citations to the full spectrum of relevant literature.Other Categories: Critical Focused Issues - consist of single articles on emerging topics of interest. Articles in this category identify problems of current interest that need to be addressed in the future in order to advance an emerging subfield of magnetism. By identifying such open issues, they focus the interest of the community to the challenges ahead. Thus, unlike review articles, this category will aim more on the future and what needs to be explored, rather than on what has been explored in the past. Of course, the articles include a review aspect in order to identify the open issues and put them into perspective. The articles need not be long, exhaustive or comprehensive. They provide the vision of the authors, who are recognized experts in the field. Readers utilize these articles to focus their thinking on future endeavors. These articles should also help to generate proposals to funding agencies worldwide. Current Perspectives - Current Perspectives consists of clusters of articles on emerging topics of interest. The articles have guest editors who formulate and manage the intellectual scope of the project. A cluster is composed of authors who represent their own perspective and who possess diverse opinions on facets of the topic. A cluster, in its totality, provides a balanced point of view, while each individual article is free to be discriminating. The articles within a cluster have invited status, the articles are typically of short-to-medium length, and the reference lists must be adequate but not necessarily extensive. The clusters are expected to focus not only on what is known, but also on what the open questions are that need to be addressed in the future. The articles should be written at a level that inspires the next generation of graduate students. The guest editors typically provide an overview article to tie the cluster together thematically. Outreach to the General Public - These are articles of a general nature that highlight the importance of magnetism and stimulate the interest of the public at large. A heightened awareness of magnetism is healthy for our field. Experts who have given public lectures will be encouraged to submit their work in order for them to reach a larger community. It will also help our readers in their own communications with the public. These articles need not be long, exhaustive or comprehensive. They provide the vision of the authors. Providing the public with the importance of magnetism and magnetic materials at a level that can be understood and appreciated will be a public service. It will also inspire a new generation of students, have a positive influence on science policy, and strengthen the case of our community in the eyes of funding agencies worldwide.
  • Chemical Physics Letters

    • ISSN: 0009-2614
    Frontier research in molecular sciences, materials and biological systemsChemical Physics Letters publishes brief reports on molecules, interfaces, condensed phases, nanomaterials and nanostructures, polymers, biomolecular systems, and energy conversion and storage.Criteria for publication are quality, urgency and impact. Further, experimental results reported in the journal have direct relevance for theory, and theoretical developments or non-routine computations relate directly to experiment. Manuscripts must satisfy these criteria and should not be minor extensions of previous work.
  • Communications in Nonlinear Science and Numerical Simulation

    • ISSN: 1007-5704
    The journal Communications in Nonlinear Science and Numerical Simulation publishes original research findings on experimental observation, mathematical modeling, theoretical analysis and numerical simulation, for more accurate description, better prediction or novel application, of nonlinear phenomena in science and engineering. It offers a venue for researchers to make rapid exchange of ideas and techniques in nonlinear science.The submission of manuscripts with cross-disciplinary approaches in nonlinear science is particularly encouraged.Topics of interest:High-dimens... Chaos, Turbulence (fluid mechanics, plasma physics, magnetohydrodynamics... nonlinear internal and surface waves, pattern formation and selection, non-Newtonian fluid flows)Hamiltonian Systems and Applications (atomic and molecular physics, accelerator physics, chemical physics, celestial mechanics and astronomy, plasma physics)Time-Series and Signal Analysis, Experimental Methods and Measurements (methods for signal analysis, models in economics and finance, laboratory experiments)Biologic... Physics (ecology and environmental science, climate modeling, bioengineering, biomechanics, biological data, neuronal systems, cardiac dynamics, haemodynamics, epidemic models and dynamics of infectious diseases, experimental and theoretical analysis in life sciences)Complexity and Networks (neural networks, complex network, engineering oriented complex systems, artificial intelligence and machine learning, sociophysics)Synchro... Lyapunov Analysis and Control (Lyapunov theory in dynamical systems, synchronization in complex systems, optimization and control)Nonlinear Mechanical Systems (MEMS and NEMS devices, continuous mechanics of solids, robotics, viscoelasticity and plasticity, energy production, conversion and storage, acoustics, nonlinear vibrations, nonlinear acoustics, porous media, granular matter)Bifurcations, Attractors and ChaosComputational Methods (modeling, analysis and simulations, numerical methods for ordinary and partial differential equations, symbolic computational methods)Analytical Methods (exact solutions for nonlinear differential equations, asymptotic methods in nonlinear dynamics, Lie group analysis, integrable systems and solitons, symbolic dynamics)Discrete, Stochastic and Hybrid Dynamics (discontinuous dynamical systems, hybrid systems, stochastic processes)Fractional Dynamics (fractional dynamics and control, fractional calculus)No length limitation for contributions is set, but only concisely written manuscripts are published. Brief papers are published on the basis of Short Communications. Discussions of previously published papers are welcome.
  • Reactive and Functional Polymers

    • ISSN: 1381-5148
    An International Journal devoted to their Science and TechnologyReactive & Functional Polymers provides a forum to disseminate original ideas, concepts and developments in the science and technology of polymers with functional groups, which impart specific chemical reactivity or physical, chemical, structural, biological, and pharmacological functionality. The scope covers organic polymers, acting for instance as reagents, catalysts, templates, ion-exchangers, selective sorbents, chelating or antimicrobial agents, drug carriers, sensors, membranes, and hydrogels. This also includes reactive cross-linkable prepolymers and high-performance thermosetting polymers, natural or degradable polymers, conducting polymers, and porous polymers.Original research articles must contain thorough molecular and material characterization data on synthesis of the above polymers in combination with their applications. Applications include but are not limited to catalysis, water or effluent treatment, separations and recovery, electronics and information storage, energy conversion, encapsulation, or adhesion.Full-length papers, perspectives and review articles will be considered. We welcome cutting-edge, original research within our scope. Modelling and simulation work will be considered only when linked to new or previously published experimental results. Lack of originality and novelty, insufficient molecular characterisation, or poor comparison with the current state of the art are reasons for rejection.
  • Journal of Photochemistry and Photobiology B: Biology

    • ISSN: 1011-1344
    The Journal of Photochemistry and Photobiology B: Biology provides a forum for the publication of papers relating to the various aspects of photobiology, as well as a means for communication in this multidisciplinary field.The scope includes: • Bioluminescence • Chronobiology • DNA repair • Environmental photobiology • Nanotechnology in photobiology • Photocarcinogenesis • Photochemistry of biomolecules • Photodynamic therapy • Photomedicine • Photomorphogenesis • Photomovement • Photoreception • Photosensitization • Photosynthesis • Phototechnology • Spectroscopy of biological systems • UV and visible radiation effects and vision.
  • Scripta Materialia

    • ISSN: 1359-6462
    Scripta Materialia is a LETTERS journal of Acta Materialia, providing a forum for the rapid publication of short communications on the relationship between the structure and the properties of inorganic materials. The scope and aims of Scripta Materialia are identical to Acta MaterialiaScripta Materialia prioritizes papers that significantly move the field forward, advancing the thinking in the field and providing mechanistic processing-structure... connections. Explorations of such connections by experiment, computation, theory, data science, and machine learning are all welcome; studies that connect across theory, computation, and experiment through mechanistic means are especially relevant. Materials structure at all scales is of interest, from electronic, atomic, and molecular arrangements to microstructural elements, including crystal defects, polycrystalline and polyphase structures, and spanning to macrostructures formed by processing that impact properties and performance. The connection of these structural features to all kinds of properties is of interest, including mechanical and functional properties, thermodynamics and kinetics, phase transformations, etc. In addition to original contributions, Scripta Materialia p... comments on papers published in Acta Materialia and Scripta Materialia. The journal also publishes Viewpoints, which are invited short articles focused on topics of current interest within the scope of the journal and coordinated by invited guest editors.
  • Computational Materials Science

    • ISSN: 0927-0256
    The aim of the journal is to publish papers that advance the field of computational materials science through the application of modern computational methods alone or in conjunction with experimental techniques to discover new materials and investigate existing inorganic materials, such as metals, ceramics, composites, semiconductors, nanostructures, 2D materials, metamaterials, and organic materials, such as polymers, liquid crystals, surfactants, emulsions, and also hybrid materials combining both inorganic and organic components such as polymer nanocomposites, nanocrystal superlattices or surfactant nanoparticle mixtures.Papers that report on the development of new methods, enhancement of existing approaches or significant technical computational advances are of interest.Papers with a focus on simulations must contain new conceptual or computational advances. For example, molecular dynamics using standard force fields, ordinary techniques and reporting conventional average quantities will be rejected without review. Validation of non-first-principles methods and transferability of methods must be included as part of each submission. In-depth discussion of impact, physical properties, and motivation for the system under study is strongly recommended.Studies including experimental data are of interest, but they must address a relevant theoretical/computat... question. Papers that are deemed to be primarily experimental with some supporting theory will be returned without review.Data-driven techniques in materials research, including machine-learning enhanced simulations and materials informatics, have emerged as powerful techniques to complement traditional computational materials science. Consistent with established best practices in across data-driven science, it is important that studies proposing or applying data-driven techniques provide data and code that adhere to FAIR data principles- Findable, Accessible, Interoperable, and Reusable. FAIR data access also ensures a robust peer review process where results can be reproduced by referees. Papers that are deemed to be primarily methodological but do not provide FAIR data and code will be returned without review. In a few rare cases, some limitations may prevent the complete public sharing of code and data; for instance, when the data or code is subject to copyright or intellectual property. However, these cases should be rare and considered on a case-by-case basis. The scope of the journal includes:obtaining new or enhanced insights into material behavior, properties and phenomena,predicting structure-property relationships for new materials in conjunction with data informatics,novel capabilities of computational methods and algorithms, technical software and shareware, or cyberinfrastructures... are accepted in the form of critical reviews, articles, letters and perspectives. Occasional special issues will be organized around a particular theme and some of these will be guest edited.Not all topics that potentially fall under the category of computational materials science will be considered; to find out more please visit the Guide for Authors.Guide for Authors:Research articles will be assessed based on originality, uniqueness and scientific merit. Manuscripts with significant overlap with existing reported works are likely to be inadmissible.To be considered for publication in Computational Materials Science studies proposing or applying data-driven techniques must exhibit a high degree of novelty in application and interpretation, in addition to providing FAIR-compatible data and code to support their analysis. the data and code used to generate your models are not available. This is achievable in different ways, not limited to posting code on a publicly available GitHub repository and/or data on Zenodo, including the code and data as attachments to the manuscript, or as a docker container.Not all topics that potentially fall under the category of computational materials science will be considered. Submissions that emphasize small molecules or clusters, focus on the design of components for structural applications, describe performance of an electronic device, or characterize thermal or mass transport without extensive accompanying input and associated discussion from computational materials science methods are best suited for other specialized journals. Additionally, papers that focus on continuum mechanical responses of broad classes of materials are likely better suited for journals that specialize in the mechanics of materials. Papers on biomolecules, drugs, bone, or medical applications will not be considered. In addition, papers on materials such as asphalt, cement, concrete, and related materials will be rejected without review.
  • Optik

    • ISSN: 0030-4026
    International Journal for Light and Electron OpticsOptik publishes articles on all subjects related to light and electron optics and offers a survey on the state of research and technical development within the following fields:Optics:Optics design, geometrical and beam optics, wave opticsOptical and micro-optical components, diffractive optics, devices and systemsPhotoelectric and optoelectronic devicesOptical properties of materials, nonlinear optics, wave propagation and transmission in homogeneous and inhomogeneous materialsInformation optics, image formation and processing, holographic techniques, microscopes and spectrometer techniques, and image analysisOptical testing and measuring techniquesOptical communication and computingPhysiologic... opticsAs well as other related topics.Electron optics:All methods strongly related to light optics, e.g. geometrical electron optics, imaging theories and methods, GRIN optics, geometrical aberrationInstrument... and equipments for guiding, focusing and imaging of charged particles, spectrometers and beam lithographyImage reconstruction and analysis, holographic methodsIt publishes original papers and short notes on theoretical and experimental research in English. OPTIK addresses itself especially to scientific and technical working specialists in this field.Contact: Optik - International Journal for Light and Electron Optics [email protected]
  • Chemical Physics

    • ISSN: 0301-0104
    Frontier research on physical phenomena in chemistry, biology and materials scienceCriteria for publication in Chemical Physics are novelty, quality and general interest in experimental and theoretical chemical physics and physical chemistry. Articles are welcome that deal with problems of electronic and structural dynamics, reaction mechanisms, fundamental aspects of catalysis, solar energy conversion and chemical reactions in general, involving atoms, molecules, proteins, clusters, surfaces, interfaces and bulk matter. Reports on new methodologies and comprehensive assessments of existing ones, as well as applications to new types of problems are especially welcome. Experimental papers are expected to be brought into relation with theory, and theoretical papers should be connected to present or future experiments. Manuscripts that apply standard methods to specific physical-chemical problems and/or to specific systems are appropriate if they report novel results for an important problem of high interest and/or if they provide significant new insights.Manuscripts describing routine use or minor extensions or modifications of established and/or published experimental and theoretical methodologies are not appropriate for the journal. In addition, manuscripts describing analytical procedures that use established spectroscopic techniques, such as for sample characterization, will not be accepted for publication, even if they appear new or improved with respect to procedures previously used.In addition to regular research papers, Chemical Physics publishes invited perspectives articles (called ChemPhys Perspectives) and Special Thematic Issues. Each Chemical Physics Special Issue provides a snapshot of the leading edge in current research of a particular field in chemical physics, and contains invited articles by specialists in that field. The objective is to create a collection of articles representative of the newest findings in a field and equivalent to that covered at a topical conference.
  • Physics Letters A

    • ISSN: 0375-9601
    The journal Physics Letters A offers a rapid review and publication outlet for novel theoretical and experimental frontier physics.The journal covers the following topics:Condensed matter physics,Quantum information (including artificial intelligence and machine learning),Nonlinear science,Statistical physics,Mathematical and computational physics,AMO and physics of complex systems,Plasma and fluid physics,Optical physics,General and cross-disciplinary physics,Biological physics and nanoscience,Astrophy... Particle physics and Cosmology.Physics Letters A also publishes Invited Perspective Articles focusing on break-through research in physics.Note to authors: If you wish to be considered for an Invited Perspective Article please contact the Editors. Physics Letters A does not publish articles on High Energy and Nuclear Physics. Plagiarism, or copying text or results from other sources, is unethical behavior and is not tolerated at Physics Letters A. All manuscripts submitted to Physics Letters A will be checked for originality using the CrossCheck database. For more information on CrossCheck please visit http://www.crossref....
  • Photonics and Nanostructures - Fundamentals and Applications

    • ISSN: 1569-4410
    The Journal features mainly original research work in experiment, theory and applications related to nanophotonic structures. Papers suitable for publication significantly advance our understanding of nanophotonic materials and structures and cover topics such as:• Metamaterials and metasurfaces; • Photonic crystals and related micro- and nanophotonic materials; • Investigation and characterization of photonic crystal properties such as optical nonlinearities, photonic band gap effects, spontaneous emission; • Fabrication of nanophotonic structures and devices using various methods, including lithography, self-assembly, holography, etc.; • Subwavelength optics of structured materials; • Metallic and metallo-dielectric nanophotonic structures; • Subwavelength structures for terahertz optics; • Plasmonics; • Chiral and bianisotropic media; • Structured photonic topological insulators and optics of PT-symmetric nanostructures; • Optics of nanostructured 2D materials; • Random and complex structured optical media; • Frequency selective surfaces; • High-impedance surfaces; • Metamaterials for antenna and circuit technology; • Metamaterial-based devices; • Acoustic and elastic metamaterials; • Photonic crystal fibers and "holey" fibers; • Integration of photonic crystals; • Micro-optical-electr... (MOEMS); • Nanostructured optical microcavities and photonic "dots"; • Inverse design and machine-learning-dri... design of nanophotonic structures; • Novel approaches to micro- and nanophotonics; • Critical assessment of new application fields (light sources, lasers, biophotonics, detectors, optical components, atom and molecule confinement).
  • Physics Reports

    • ISSN: 0370-1573
    A Review Section of Physics LettersThe journal Physics Reports publishes timely reviews which are more extensive than just literature surveys but normally less than a full monograph. Each report deals with one specific subject and is generally published in a separate volume. These reviews are specialist in nature but contain enough introductory material to make the main points intelligible to a non-specialist. The reader will not only be able to distinguish important developments and trends in physics but will also find a sufficient number of references to the original literature.Starting in 2025, Physics Reports will inaugurate a new "Rapid Reviews” section. Rapid Reviews are intended to be shorter reviews, which can be completed more quickly (on order three months) than regular reviews, on exciting new subjects. They are intended to reach a broader audience but go into less technical detail than a regular Physics Reports review. The target length is on order 20 pages (as opposed to regular reviews, which are intended to be more than 50 journal pages) and the reviews are intended to allow more in the way of editorializing than regular articles, which are intended to be more balanced, complete, and pedagogical. We aim to publish one such Rapid Review per month.The topics covered by the journal include but are not limited to:Astrophysics and Cosmology,Atomic, Molecular and Optical Physics,Biological Physics,Condensed Matter Physics,High Energy Physics,Nanoscience,... Dynamics and Complex Systems,Nuclear Physics and Hadronic Physics,Plasma Physics,Statistical Physics.Submission of articles to Physics Reports is by invitation only; unsolicited submissions cannot be accepted. Should you feel that you have a topic suitable for publication in one of the sections in this journal, please contact our Editorial Office physrep-eo@elsevier.... ,  with a proposal of no more than 1000 words. You must specify which Editor should review your proposal (see Editorial Board).
  • Chaos, Solitons & Fractals

    • ISSN: 0960-0779
    An interdisciplinary journal of nonlinear science.Chaos, Solitons & Fractals aims to be the leading journal in the interdisciplinary field of Nonlinear Science.It encourages the submission of high-quality articles (under the form of short communications, regular papers, and review papers) containing results which have a significant impact on the following subjects:nonlinear dynamics and non-equilibrium processes in physics and applied mathematics;complex matter and networks;biophysics, systems biology and computational biology;fluctuations and random processes;artificial intelligence, machine learning and big data analytics;self-organ... and emergent phenomena;applicatio... to social science, engineering and econophysics.The journal can only accept papers whose primary subject area lies within the above Aims & Scope.In particular, please take notice of the following, additional, criteria:In order to be acceptable, manuscripts of more mathematical nature should have a clear and explicit connection to physical insight or new qualitative features. The word "Solitons" should be understood as a label especially extended to all nonlinear integrable systems in complex natural phenomena. The paper should not bear on some explicit formulae, some standard solutions, constructions, or asymptotic methods.The journal is interested in articles providing strong insights in the mathematical theory of fractals that are profound for an important particular application, especially in complex systems. Numerical computations should only assist the developed results.The submitted Manuscripts should contain presentations which are a) of interdisciplinary interest, b) easily accessible also to a non-specialized-audi... and c) written in an excellent English style.Notice that if the above criteria are not fulfilled, submissions may be desk-rejected by the Journal's Editors without being sent to reviewers.
  • Physics of the Dark Universe

    • ISSN: 2212-6864
    Physics of the Dark Universe is a hybrid journal which aims to provide a flexible platform for the publication of peer reviewed articles in various formats within the fields of Dark Matter, Dark Energy, Early Universe, Gravitational waves and Neutrinos, covering all theoretical, experimental and phenomenological aspects. The Journal welcomes submissions for articles in the following sections: Dark Matter: Models for the cosmological dark matter, including, but not limited to, particle-like, wave-like, black holes; Experimental and observational probes Dark Energy: Models and theoretical scenarios related to the late-time cosmic acceleration; Observations and experimental results; Forecast and design of new experiments Early Universe: Models and observational tests of the pre-recombination Universe, including but not limited to inflation Early universe probes of fundamental physics Dark Messengers: Multiwavelength/mult... messenger astrophysics, including but not limited to: Gravitational waves; Cosmic rays; Dark-sector particles and fields; Black hole-related observations (e.g. black hole shadows) Software Description and Manuals can also be published, if the software is proved to have scientific interest in the understanding of Dark Matter and Dark Energy. The paper can be enriched with (part of) the code itself, or the software and code can be separately published in the Open Access journal SoftwareX (https://www.journal... which hosts software in a curated GitHub Repository. The journal gives authors a platform to showcase their best research in a flexible journal that supports a variety of peer-reviewed article types: short communications, full length articles, letters, review articles, reports, selected articles from conferences (conference proceedings), workshops, invited perspectives, editor's choice, white papers of new experiments and special issues. For more information about Special issues publication please contact our Content Acquisition Specialist and Publisher. Note: Please note that for submissions on modified theories of gravity and black hole thermodynamics, we will only consider for peer review those deemed of exceptional impact, with novel, relevant, and impactful results. These restrictions apply in particular to f()-type models of gravity, dynamical systems analyses of modified gravity models, and cosmological tests of modified gravity models based only data sensitive to the background expansion (as opposed to perturbations).
  • Journal of Computational Physics

    • ISSN: 0021-9991
    The Journal of Computational Physics (JCP) focuses on the computational aspects of physical problems. JCP encourages original scientific contributions in advanced mathematical and numerical modeling reflecting a combination of concepts, methods and principles which are often interdisciplinary in nature and span several areas of physics, mechanics, applied mathematics, statistics, applied geometry, computer science, chemistry and other scientific disciplines as well: the Journal's editors seek to emphasize methods that cross disciplinary boundaries.JCP also encourages the submission of papers that develop innovative methods bridging mathematical, physical modeling and algorithmization, e.g. at the frontier between predictive simulation and machine learning. When addressing problems previously covered by other approaches, a comparison should be provided. As for any paper in JCP, the efficacy, robustness, computational complexity, as well as reproducibility should be addressed.JCP also publishes short notes of 4 pages or less (including figures, tables, and references but excluding title pages). Letters to the Editor commenting on articles already published in this Journal will also be considered. Neither notes nor letters should have an abstract. Review articles providing a survey of particular fields are particularly encouraged. JCP does not impose a formal page limit. Authors are expected to present their work clearly and concisely. The handling Editor will assess whether the length of the manuscript is appropriate for the content and may request a shorter version of the submission if necessary. Published conference papers are welcome provided the submitted manuscript is a significant enhancement of the conference paper with substantial additions.Reproducib... that is the ability to reproduce results obtained by others, is a core principle of the scientific method. As the impact of and knowledge discovery enabled by computational science and engineering continues to increase, it is imperative that reproducibility becomes a natural part of these activities. The journal strongly encourages authors to make available all software or data that would allow published results to be reproduced and that every effort is made to include sufficient information in manuscripts to enable this. This should not only include information used for setup but also details on post-processing to recover published results.
  • Annals of Physics

    • ISSN: 0003-4916
    Annals of Physics presents original work in all areas of basic theoretic physics research. Ideas are developed and fully explored, and thorough treatment is given to first principles and ultimate applications. Annals of Physics emphasizes clarity and intelligibility in the articles it publishes, thus making them as accessible as possible. Readers familiar with recent developments in the field are provided with sufficient detail and background to follow the arguments and understand their significance.The Editors of the journal cover all fields of theoretical physics. Articles published in the journal are typically longer than 20 pages.