2023 Impact factor 1.8
Soft Matter and Biological Physics


EPJ H Highlight - Quantum Gravity, Effective Field Theory, and Strings


A historical overview of different approaches to the quantum theory of gravitation from the early twentieth century shows how they have been combined to set our modern view of a unified ‘theory of everything’.

Gravity is one of four fundamental interactions. The most precise description of this force is still provided by Einstein’s General Theory of Relativity, published in 1915, an entirely classical theory. This description sets gravity apart from the other three forces - strong, weak, and electromagnetism - all described by quantum fields. Therefore, any attempt to unify the four forces must depend on a description of gravity that uses the principles of quantum mechanics. This has been an active area of theoretical physics since the 1930s. A historian and a physicist, Alessio Rocci from VUB in Brussels and Thomas Van Riet from KU Leuven in Belgium have set out a historical overview of the development of quantum theories of gravity to explain our current view on a future unified theory of the four forces. This work has now been published in the journal EPJ H: Historical Perspectives on Contemporary Physics.


EPJ Plus Highlight - A guide for early-career researchers in computational science

A navigable guide for graduate students. Credit: ErrantScience

A new article offers a valuable guide for new graduate students starting out their careers in computational science.

In recent years, a growing number of students have embraced scientific computation as an integral component of their graduate research. Yet since many of them are new to the field, they often have little to no coding experience, or any prior knowledge of computational tools. For many students starting out in the field, this can seem daunting, and leaves them unsure of where to start.

In a new article published in EPJ Plus, a team led by Idil Ismail, a current graduate student at the University of Warwick, UK, present an introductory guide to the field for researchers embarking on new careers. The team's work will help new graduate students to navigate the complexities of scientific computation science as they begin their journey in computational science research and could ultimately help the wider field to become more transparent and inclusive.


Konstantinos Bachas joins the EPJ Scientific Advisory Committee (SAC)

Konstantinos Bachas

The Scientific Advisory Committee of EPJ is delighted to welcome Professor Konstantinos Bachas, as the new representative for the Hellenic Physical Society.

Konstantinos (Dinos) Bachas is an Associate Professor at the University of Thessaly in Greece, specializing in experimental high energy physics. His research focuses on topics related to the physics of the LHC at CERN and the ATLAS experiment. These include searches for new physics using advanced statistical methods, Standard Model measurements mainly in diboson production channels, and various simulation and reconstruction tasks for the ATLAS Muon Spectrometer. In recent years, his experimental efforts have involved the use of machine learning techniques for analyzing high energy physics data, exploring searches for hypothetical resonances, and searching for new physics within the context of Effective Field Theories.

Outside of his research, Professor Bachas is dedicated to education and outreach, having taught a wide range of courses from accelerators and detectors in nuclear and particle physics to the experimental foundations of elementary particle physics.

EPJ Web of Conferences Highlight - WONDER-2023 - 6th International Workshop On Nuclear Data Evaluation for Reactor applications

By combining experimental data (yellow boxes: example of experimental setup and apparatus) and theoretical calculations (red boxes: example of theoretical approaches), it becomes possible to perform an evaluation of nuclear data for several applications (middle: example of a nuclear reactor). Those evaluated nuclear data are collected in a regularly updated public international library such as JEFF (Joint Evaluated Fusion and Fission).

To describe the path of neutrons in the material but also the chain reactions that take place in a reactor and the changes in the composition of matter due to nuclear reactions, neutronics uses computer codes.

These codes have also acquired such a level of performance since the last two decades that the main source of uncertainty in neutronic calculations comes today from nuclear data.

In this context, the 6th edition of the International Workshop On Nuclear Data Evaluation for Reactor applications (WONDER-2023), organized by the CEA-IRESNE and the Cadarache center, in collaboration with the NEA (Nuclear Energy Agency of the OECD) and with the support of the “Aix-Marseille metropole”, was held in Aix-en-Provence (France), on June 2023.


EPJ Plus Highlight - Describing growing tissues in the language of thermodynamics

Nematic properties determine the structure and the shape of the aggregate.

New analysis shows how key properties of biological tissues can be accurately described in the mathematical language of Onsager’s variational principle, widely used to describe continually changing systems in thermodynamics.

A key feature of biological tissues is their inhomogeneity and their ability to grow via cell reproduction. To study this behaviour, it is important to describe it using equations, which account for factors including growth rates, chemical signalling, and tissue structure.

In doing this, researchers aim to develop consistent continuous descriptions of these deeply complex systems: accurately predicting properties such as cell reproduction rates, disorder, and how their growth varies in different space directions, depending on their interactions.

Through new analysis published in EPJ Plus, Joseph Ackermann and Martine Ben Amar at Sorbonne University Paris, show that tissue development can be reliably captured within ‘Onsager’s variational principle’: a mathematical framework used widely in thermodynamics.


EPJ D Highlight – Estimating uncertainty in atomic spectroscopy

Many papers added to NIST databases mention atomic spectroscopy topics. Few of these include uncertainty estimates. Credit: A. Kramida (2024)

A numerical toolbox offers a robust way to evaluate uncertainty in atomic wavelength measurements.

If you repeat a measurement with the same or different instruments, you’ll get slightly different numbers each time. Estimating the uncertainties associated with these numbers turns them into an informative result. In a study published in EPJ D, Alexander Kramida, of the National Institute of Standards and Technology in Maryland, USA, now explains a new statistical approach for estimating the uncertainty associated with atomic spectroscopy measurements. He discusses how this approach can be applied both to measurements of spectral line wavelengths, and to other atomic properties that are indirectly determined from them.


EPJ Web of Conferences Highlight - mm Universe 2023 - Observing the Universe at mm Wavelengths

mm Universe 2023 conference held in Grenoble (France).

The mm Universe 2023 conference is the third edition in a series of biennial workshops. It is devoted to the observations of the sky at millimetre wavelengths, which has contributed to tremendous improvements in our understanding of a great variety of scientific topics ranging from the star formation in the Milky Way to the measurement of cosmological parameters.

The mm Universe 2023 conference held in Grenoble (France), from 26 to 30 June 2023, has been organized by LPSC (CNRS and Université Grenoble Alpes). With more than a hundred of attendees from 14 countries, it brought together the scientific community working on topics related to the mm Universe, spanning from stellar to cosmological scales.


EPJ ST Highlight - CompactLight: Designing a Cost-Effective XFEL Facility

An international group of experts has produced a design for a free electron X-ray laser facility that is significantly smaller and cheaper than those that are currently in use.

Very many advances in structural science since the 1970s were made by probing materials with synchrotron radiation: that is, high energy X-rays generated through accelerating high-energy electrons. The latest generation of such sources, X-ray free electron lasers (XFEL) are far more powerful than their predecessors, but are only accessible to international consortia and a few rich countries because of their high cost. Now, an international group of experts have prepared a design for a more compact and cost-effective XFEL system, accessible to small countries and, perhaps, some individual laboratories. The design is published in EPJ Special Topics (EPJ ST).


Focus Point on Physics in the Balkans: Perspectives and Challenges

Guest editors: Luc Bergé, Goran S. Djordjević and Zoran V. Popović

One specificity of physics in the Balkans is the existence of a tradition, more than 30 years long, of organizing triennial Balkan congresses (International General Physics Conferences) within the Balkan Union of Physicists (BPU) as a platform for the presentation of the research results of hundreds of participants and their collaborators with the Balkans, from Europe and the world.

The aim of this Focus point of EPJ Plus is to contribute to an overview of the state of the art of research in physics in the Balkans. Eleven of the seventeen plenary and invited lecturers at the BPU11 Congress contributed to this issue. The Focus Point provides valuable insights and highlights results in already established areas, as well as some interesting new research avenues to pursue. This issue contains mainly original scientific papers with review elements in the fields of Solid State Physics, Physics of Materials, Econophysics, Quantum Optics and Laser Physics, Open Quantum Systems, Cosmic Rays and Hubble Tension in Cosmology, Nuclear and Collider Physics.

All articles are freely accessible until 31 May 2024. For further information, read the Editorial.

T. Mihaescu, A. Isar, Irreversibility and entropy production in two coupled bosonic modes interacting with a thermal environment. Eur. Phys. J. Plus 139, 82 (2024). https://doi.org/10.1140/epjp/s13360-024-04869-x

D. Joković et al., Application of Geant4 simulation in measurement of cosmic-ray muon flux and studies of muon-induced background. Eur. Phys. J. Plus 138, 1006 (2023). https://doi.org/10.1140/epjp/s13360-023-04639-1

V.V. Gligorov, V. Reković, Review of real-time data processing for collider experiments. Eur. Phys. J. Plus 138, 1005 (2023). https://doi.org/10.1140/epjp/s13360-023-04599-6

D. Huterer, Hubble tension. Eur. Phys. J. Plus 138, 1004 (2023). https://doi.org/10.1140/epjp/s13360-023-04591-0

B. Arbutina, Nonlinear diffusive shock acceleration of cosmic rays: quasi-thermal and non-thermal particle distributions. Eur. Phys. J. Plus 138, 863 (2023). https://doi.org/10.1140/epjp/s13360-023-04500-5

C. Farcău, Linear arrays of metal-coated microspheres: a polarization-sensitive hybrid colloidal plasmonic–photonic crystal. Eur. Phys. J. Plus 138, 827 (2023). https://doi.org/10.1140/epjp/s13360-023-04638-2

L. Stoyanov et al., Optical vortices in brief: introduction for experimentalists. Eur. Phys. J. Plus 138, 702 (2023). https://doi.org/10.1140/epjp/s13360-023-04227-3

D.B. Milošević, Application of quantum-orbit theory to atomic processes in strong tailored laser fields and terahertz pulses. Eur. Phys. J. Plus 138, 356 (2023). https://doi.org/10.1140/epjp/s13360-023-03962-x

E.V. Monaico et al., Gold coated microstructures as a platform for the preparation of semiconductor-based hybrid 3D micro-nano-architectures. Eur. Phys. J. Plus 138, 827 (2023). https://doi.org/10.1140/epjp/s13360-023-04462-8

Z. Popović, P. Miranović, Current–voltage characteristics and conductance spectra in s-wave or d-wave superconductor/ferromagnet/superconductor heterojunctions: role of Andreev reflection. Eur. Phys. J. Plus 138, 767 (2023). https://doi.org/10.1140/epjp/s13360-023-04394-3

M. Maragakis et al., Tracing technological shifts: time-series analysis of correlations between patent classes. Eur. Phys. J. Plus 138, 776 (2023). https://doi.org/10.1140/epjp/s13360-023-04344-z

Adam Maj joins the EPJ Scientific Advisory Committee (SAC)

Adam Maj

The Scientific Advisory Committee of EPJ is delighted to welcome Professor Doctor Adam Maj, as the new representative for the Polish Physical Society.

Adam Maj is a professor of physics and the head of the Division of Nuclear Physics and Strong Interactions in the Institute of Nuclear Physics Polish Academy of Sciences (IFJ PAN), Krakow, Poland, and he coordinates the nuclear physics research program at the Cyclotron Center Bronowice at IFJ PAN. In the past he was the Scientific Director of this institute. He is a member of the NUPPEC committee, member of the Governing Board of the Polish Physical Society and member of the Editorial Board of Physical Review C. His interests are experimental nuclear physics, especially the gamma-spectroscopy, the gamma-decay of giant and pygmy resonances, hot rotating nuclei, high spin physics, novel scintillator detectors, popularization of science.

F. Croccolo, G. Fragneto and H. Stark
My co-author [...] and I have carefully examined the new proofs. They look fantastic, and we greatly appreciate the expert work of the Production Office staff [...]

Jane E.G. Lipson, Department of Chemistry, Dartmouth College, Hanover, NH, USA

ISSN (Print Edition): 2429-5299
ISSN (Electronic Edition): 2725-3090

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