Mutual Annihilation Research Articles

Meron-Mediated Phase Transitions in Quasi-Two-Dimensional Chiral Magnets with Easy-Plane Anisotropy: Successive Transformation of the Hexagonal Skyrmion Lattice into the Square Lattice and into the Tilted FM State.

I revisit the well-known structural transition between hexagonal and square skyrmion lattices and subsequent first-order phase transition into the tilted ferromagnetic state as induced by the increasing easy-plane anisotropy in quasi-two-dimensional chiral magnets. I show that the hexagonal skyrmion order first transforms into a rhombic skyrmion lattice, which, adjusts into a perfect square arrangement of skyrmions ("a square meron-antimeron crystal") within a narrow range of anisotropy values. These transitions are mediated by merons and anti-merons emerging in the boundaries between skyrmion cells; energetically unfavorable anti-merons annihilate, whereas pairs of neighboring merons merge. The tilted ferromagnetic state sets in via mutual annihilation of oppositely charged merons; as an outcome, it contains bimeron clusters (chains) with the attracting inter-soliton potential. Additionally, I demonstrate that domain-wall merons are actively involved in the dynamic response of the square skyrmion lattices. As an example, I theoretically study spin-wave modes and their excitations by AC magnetic fields. Two found resonance peaks are the result of the complex dynamics of the domain-wall merons; whereas in the high-frequency mode the merons rotate counterclockwise, as one might expect, in the low-frequency mode merons are instead created and annihilated consistently with the rotational motion of the domain boundaries.

Deterrence asymmetry and strategic stability in Europe

ABSTRACT Strategic stability can mitigate the security dilemma that mutual deterrence efforts produce. If two parties agree on what the most destabilising peacetime or wartime behaviour is, they are more likely to agree on risk-reduction measures. However, contemporary security actors rarely share views of what constitutes destabilising behaviour, given political disagreements and asymmetries in deterrent measures due to varying military capabilities, technology adaptations and threat perceptions. This paper examines the deterrence dynamics between NATO and Russia, demonstrating how asymmetric views of strategic stability add potential security dilemmas to the already-severe political confrontation between them.

The US-China Rivalry in the Middle East: Confrontation or Competitive Coexistence

A new era of great power rivalry has returned to the center of the global stage. The Middle East has emerged as one of the key arenas where this rivalry is being played out, and analyzing it through the lens of power transition theory provides valuable insights into the dynamics at play. This study focuses on the great power rivalry between the United States and China in the Middle East through the lens of power transition theory. It examines whether this great power rivalry in the region will allow them to pursue competitive coexistence or if they can expect increasing levels of confrontation and mutual deterrence. The study maintains that the US-China rivalry in the Middle East is multidimensional and spans primarily three dimensions: geo-economic (the Belt and Road Initiative framework), geopolitical (partnership diplomacy), and the race for technological supremacy (the Digital Silk Road). While conflict is not inevitable, it is essential to recognize the potential for confrontation and build a coordinated mechanism to manage and mitigate these tensions.

"Polymerization" of Bimerons in Quasi-Two-Dimensional Chiral Magnets with Easy-Plane Anisotropy.

We re-examine the internal structure of bimerons, which are stabilized in easy-plane chiral magnets and represent coupled states of two merons with the same topological charge |1/2| but with opposite vorticity and the polarity. We find that, in addition to the vortices and antivortices, bimerons feature circular regions which are located behind the anti-vortices and bear the rotational sense opposite to the rotational sense chosen by the Dzyaloshinskii-Moriya interaction. In an attempt to eliminate these wrong-twist regions with an excess of positive energy density, bimerons assemble into chains, and as such exhibit an attracting interaction potential. As an alternative to chains, we demonstrate the existence of ring-shaped bimeron clusters of several varieties. In some rings, bimeron dipoles are oriented along the circle and swirl clockwise and/or counterclockwise (dubbed "roundabouts"). Moreover, a central meron encircled by the outer bimerons may possess either positive or negative polarity. In other rings, the bimeron dipoles point towards the center of a ring and consequently couple to the central meron (dubbed "crossings"). We point out that the ringlike solutions for baryons obtained within the Skyrme model of pions, although driven by the same tendency of the energy reduction, yield only one type of bimeron rings. The conditions of stability applied to the described bimeron rings are additionally extended to bimeron networks when bimerons fill the whole space of two-dimensional samples and exhibit combinations of rings and chains dispersed with different spatial density (dubbed bimeron "polymers"). In particular, bimeron crystals with hexagonal and the square bimeron orderings are possible when the sides of the unit cells represent chains of bimerons joined in intersections with three or four bimerons, respectively; otherwise, bimeron networks represent disordered bimeron structures. Moreover, we scrutinize the inter-transformations between hexagonal Skyrmion lattices and disordered bimeron polymers occuring via nucleation and mutual annihilation of merons within the cell boundaries. Our theory provides clear directions for experimental studies of bimeron orderings in different condensed-matter systems with quasi-two-dimensional geometries.

Analysis of the chemical diffusion master equation for creation and mutual annihilation reactions

We propose an infinite dimensional generating function method for finding the analytical solution of the so-called chemical diffusion master equation (CDME) for creation and mutual annihilation chemical reactions. CDMEs model by means of an infinite system of coupled Fokker–Planck equations the probabilistic evolution of chemical reaction kinetics associated with spatial diffusion of individual particles; here, we focus an creation and mutual annihilation chemical reactions combined with Brownian diffusion of the single particles. Using our method we are able to link certain finite dimensional projections of the solution of the CDME to the solution of a single linear fourth order partial differential equation containing as many variables as the dimension of the aforementioned projection space. Our technique extends the one presented in Lanconelli [J. Math. Anal. Appl. 526, 127352 (2023)] and Lanconelli et al. [arXiv:2302.10700 [math.PR] (2023)] which allowed for an explicit representation for the solution of birth-death type CDMEs.

Romantic Painters on Art

Philipp Otto Runge and Caspar David Friedrich, well known Romantic painters, were not only notable masters of the brush but also theorticians of art. The present essay is devoted to an analysis of their theories. Its novelty consists in the fact that it analyzes for the first time the theoretical views that are expressed in the texts of both artists. Runge’s charactertistic feature is a pantheistic experience of God. According to him, it must be expressed in art. He proposes his own dialectic of being, which essentially consists of development, struggle, and mutual annihilation of opposite elements at the moment of achieving perfection. It is precisely this dialectic that, according to him, forms the foundation of art, where he sees an opposition between feeling and reason. Runge pays special attention to the notion of the “spirit of art,” which appears on the basis of the feeling of mutual connection between the human being and the universe, as well as of the artist’s foresentiment of God. In its foundation, art is symbolic and therefore close to religion. The spirit of art manifests itself in what one can call the music, poetry, or symbolism of a work of art. In art, Friedrich sees the spiritual foundation of the world. He distinguishes between skill and “spirituality” in it. According to him, one can master the skill, but one inherits spirituality from birth, and few artists possess it. As a Romantic landscape artist, he opposed illusionism in painting. He considered the creative element in art, which is born in the artist’s inner world, as pivotal. Feeling plays the principal role in art. For this reason Friedrich foregrounds the uncon-scious, although he is convinced that reason and skill must actively participate in the creative process as well. Friedrich preferred winter, foggy, and crepuscular landscapes, which expressed Romantic moods well.

Introduction of dislocation filtering with different ammonia flows in low-temperature grown AlN (< 1200 °C)

High crystalline quality of AlN layers are commonly grown at temperatures above 1200 °C. However, this work revealed that introducing a rough surface of AlN layer, defined as dislocation filtering (DF) herein, can improve the crystalline quality of 1.5 μm thick AlN layers grown at 1175 °C via metal organic vapor phase epitaxy technique. With 7 slm of ammonia flow during the DF growth, the lowest threading dislocation density (TDD) of ∼2.9 × 109 cm−2 was obtained. The result was associated to the formation of 3D growths which become reasonably smaller, denser, and more uniformly distributed with increasing ammonia flow up to 7 slm. The 3D growths were suggested to promote lateral growth that can increase the possibility for TD inclination and hence, mutual annihilation. The 3D growths characteristic disappeared when the ammonia flow was 10 slm. The optimized AlN layer that was obtained with 7 slm of ammonia flow exhibited an atomically smooth surface with a few deep trenches and improved transparency. Meanwhile, the calculated in-plane tensile strain for the AlN layers grown on DF with 1–7 slm of ammonia was about 3 times higher than the AlN layer without DF. However, no evidence of microcracks on the surface was observed.

US Deterrence against Russia and China (based on strategic documents of J. Biden administration)

The contemporary world order is rapidly changing, which is manifested, inter alia, in the growing erosion of the US global military superiority. This trend is acknowledged in the US military-strategic and policy planning documents. In this context the strengthening of the military potential of both the Russian Federation and the PRC, coupled by the expansion of political and economic cooperation between them, is a matter of particular concern for the US ruling elites. At the same time, recognizing a problem does not mean assessing it correctly. A closer examination of key strategic documents published in recent years shows that if from a political and military point of view, the US strategists come up with a generally rational list of measures aimed at countering the challenge, posed by Russia and China, from an ideological point of view they doggedly follow liberal-hegemonic premises that are increasingly inconsistent with current international political realities. The author notes that the policy of D. Trump and J. Biden administrations towards China is characterized by a high degree of continuity. The main role in containing the PRC should be played by a system of military-political alliances with the countries of Southeast and South Asia located along the perimeter of its borders. In addition to the alliances inherited from the Cold War, the Biden administration is seeking to develop new ‘bloc structures’ in the Indo-Pacific region, in particular the Quadrilateral Security Dialogue (QUAD). However, not all countries in the region, in particular India, support the anti-Chinese orientation of the US initiatives. Washington’s relations with Moscow deteriorated sharply after the start of the special military operation in Ukraine, but even before that, the United States faced serious challenges in maintaining strategic parity with the Russian Federation. This primarily concerns the quantitative, rather than qualitative side of the equation: according to the US military strategists, Russia has made significant progress in modernizing its strategic nuclear forces and developing fundamentally new types of nuclear delivery vehicles. At the same time, the Biden administration’s approaches to building relations with Moscow are no less ideological than in the case of the PRC, which makes the prospects for resuming Russian-American (and ideally trilateral Russian-American-Chinese) negotiations on strategic arms control extremely vague. The question arises to what extent this ideologized foreign policy of the Biden administration meets the new international realities and the strategic interests of the United States itself.

Oppenheimer: The Man, the Movie and Nuclear Dread

Christopher Nolan’s film Oppenheimer, centred on the eponymous American physicist who steered the Manhattan Project to completion of the first nuclear bomb in 1945, captures scientists reaching their own destructive capability at its most terrible. It prompts viewers to wonder why, over the course of nearly 80 years, Oppenheimer’s nuclear dread hasn’t been embraced with greater alarm, and informed praetorian critiques haven’t been entertained more openly. The short answer is that nuclear deterrence has worked. But the movie comes at a moment when it is being tested. With its spectacular suggestions of nuclear destruction and its intense examination of early anxieties about nuclear weapons that have never been satisfactorily addressed, Oppenheimer prompts a crucial question: whether mutual deterrence, shorn of arms control and regular diplomacy and under the pressure of a major war involving nuclear powers, can still work.

Vacancy segregation and intrinsic coordination defects at (1 1 1) twist grain boundaries in diamond

High radiation damage resistance has become increasingly important for applications of functional materials in harsh environments. The high radiation damage resistance diamond cubic carbon is a unique material which is considered for radiation environments. Beyond the intrinsic radiation hardness of crystal, the interaction between point defects and interfaces (e.g., grain boundaries) increases resistance to radiation damage. In effect, grain boundaries act as sinks for point defects and promote their mutual annihilation. Furthermore, interfaces can be exploited to obtain controlled segregation of point defects, thus avoiding the degradation of material properties due to uncontrolled point defect segregation and coalescence.In the present work, we investigate the interaction between vacancies – as a radiation defect in the bulk crystal – and (1 1 1) twist grain boundaries in crystalline diamond using atomistic simulation with analytical bond order potential. Based on previous observations on structure–property relationships characterising the (1 1 1) twist grain boundaries, this work analyses the emergence of periodic segregation patterns, which are rationalised by the underlying interface structure and their periodic intrinsic coordination defect populations. This observation suggests that randomly distributed vacancies in bulk single crystals can form self-organised defect arrays in the grain boundary. The coordination defect content correlates with the interface sink efficiency, providing guidelines for designing interfaces with high sink efficiency.

What charged cosmic rays tell us on dark matter

Dark matter particles could be the major component of the haloes of galaxies. Their mutual annihilations or decays would produce an indirect signature under the form of high-energy cosmic-rays. The focus of this presentation is on antimatter species, a component so rare that any excess over the background should be easily detected. After a recap on Galactic propagation, I will discuss positrons, antiprotons and anti-nuclei. For each of these species, anomalies have been reported. The antiproton excess, for instance, is currently a hot topic. Alas, it does not resist a correct treatment of theoretical and data errors.

Ukraine’s nuclear security as a key element of the European security system

Ukraine, as a strategically located territory and an important player in the geopolitical interests of various power blocks, has become a key element of the European nuclear security system, so it is important to study the most important factors shaping the situation around nuclear weapons and take appropriate measures to avoid potential threats. The research aims to outline all aspects and factors of Ukraine’s nuclear security that directly affect the international security system, in particular, the European countries. The methodological basis of the study is a systematic analysis of information and regulatory sources, such as bilateral and multilateral international agreements, documents and materials of international organisations, documents of individual country authorities, speeches, and materials of print and electronic media. The article highlights the historical context, including the transfer of Ukrainian nuclear weapons materials to Russia following the Treaty on the Non-Proliferation of nuclear weapons. The current stage of development of the international nuclear non-proliferation regime is analysed. Attention is paid to the evolution of the regime under the influence of the confrontation between the two superpowers and the doctrine of mutual deterrence. The situation with nuclear security in Ukraine and its impact on the Black Sea region is analysed. The consequences of military actions in Ukraine and factors that create new dimensions for nuclear security, in particular in the context of control over nuclear materials and the possibilities of their use, are considered. The results of the study of the problem are presented in the description of new threats and risks that require deepening cooperation of international partners and taking effective measures to ensure nuclear safety in the region. The study emphasises the need for joint efforts to counter new challenges and minimise nuclear safety risks. The practical significance of the study is determined by strategies for cooperation with international partners to achieve stability in the field of nuclear safety

Deliberate Nuclear First Use in an Era of Asymmetry: A Game Theoretical Approach

Most nuclear dyads are characterized by some degree of nuclear and conventional asymmetry. This paper argues that these asymmetries create an environment in which deliberate nuclear first use (DNFU) can be rational. This possibility has been discarded in the formal literature on nuclear escalation because of the common reliance on the assumption of mutually assured destruction (MAD). This paper develops a formal model that traces how and under what circumstances two types of DNFU are rational. First, nuclear imbalances and advancements in counterforce technologies create a damage limitation incentive for a strong actor. Second, conventional asymmetry creates an incentive for the coercive use of nuclear weapons by the weaker player. Moreover, this paper illustrates that these asymmetric conditions are a relevant characteristic in important and very different nuclear dyads: DPRK–US, Pakistan–India, and Russia–US. Thus, the model demonstrates the potential core drivers of DNFU in today’s nuclear landscape.

Imperfect bipolarity: The ‘third power’ factor in Soviet-American relations in the nuclear field (1958–1968)

30 years after the end of the Cold War, bipolar structure still dominates in the nuclear sphere, although certain nuclear powers are closing the gap with Russia and the United States in terms of strategic arsenals and the system of world politics in general is moving towards polycentrism. At the same time, as US-Russian relations continue to deteriorate against the backdrop of the ‘Ukrainian crisis’, the prospects for strategic dialogue after the expiration of the Treaty on Measures for the Further Reduction and Limitation of Strategic Offensive Arms (New START) are becoming increasingly vague. The absence of a new agreement in this field threatens to throw international relations back to the beginning of the Cold War, with all the ensuing consequences. To avoid such a scenario, not only the leaders of Russia and the United States should demonstrate political will, but other nuclear powers should also be included in the negotiation process, particularly China. In this regard, the history of the Cold War can provide valuable lessons. The author argues that bipolarity (even at its apex in the late 1950s — early 1970s) had never been an exclusive characteristic of international relations. On the basis of a number of historical cases, the paper demonstrates that during this period the superpowers constantly had to reckon with the ‘third power’ factor. The latter did not only influence the logic and dynamics of Soviet-American relations, but also to a large extent predetermined the direction and nature of their military development and planning. Indeed, it was the ‘third power’ factor, namely China, along with the achievement of strategic parity between the superpowers that became one of the main impulses to the establishment of the non-proliferation regime. In conclusion, the author focuses on yet another important lesson from the Cold War: the experience of arms control negotiations during that period suggests that the meetings of politicians should be preceded by joint brainstorming sessions with scholars from interested countries. In the current situation, representatives of the academic community should take the lead so that by the time the political climate eventually changes, there would already be coherent and viable options for nuclear arms control adapted to new realities.

Multiscale analysis of wheel-rail rolling contact wear and damage mechanisms using molecular dynamics and explicit finite elements

As traffic density and axle loads increase, the macroscopic wheel-rail contact can lead to severe rail wear. This paper constructs a multi-scale analysis framework from macroscopic force characteristics to microscopic wear mechanisms based on explicit finite element methods and molecular dynamics models. The study shows that the mutual proximity and annihilation of reverse dislocations in the rail material under the action of wheel-rail forces is an important cause of grain boundary fragmentation, while the proliferation of dislocations on the Subsurface leads to work hardening of the rail. The analytical framework proposed in this paper achieves a multiscale correlation between wheel-rail macroscopic contact and material microscopic response, and the conclusions obtained reveal the microscopic wear mechanism of rail materials.

A benefactor to mankind? Captain Warner's secrets and the politics of invention in early Victorian Britain.

This article delves into Captain Samuel Alfred Warner's dogged campaign to sell two inventions - his submersible mine and "long range" missile - to the British government in the 1840s and 1850s. Departing from a historiography that dismisses Warner as a fraudster, it clarifies how he managed to generate widespread interest in his weapons technologies for nearly twenty years. I therefore analyze three key elements of his self-promotion: his personal branding, his pitch, and his simultaneous embrace and rejection of publicity. Neither elite nor highly educated, Warner ran up against a culture of "polite science" that distinguished disinterested practitioners from profit-minded schemers. To establish his credentials, he emphasized his practical maritime experience and represented himself as a martyr willing to bear the scorn of a disbelieving establishment. In pitching his devices, Warner capitalized on alarmism over border security and the integrity of the empire; he declared that they could hobble France's modernizing navy and quickly end colonial conflicts. When skeptics began to fret over the proliferation of his destructive weapons, Warner flipped the script and lauded the threat of mutual annihilation as a deterrent to needless warfare. The issue of publicity, however, would ultimately be Warner's professional undoing. Despite successful demonstrations, his clashes with official investigators and his refusal to disclose his chemical secrets led critics to dispute the originality of his discoveries. An examination of Warner's self-promotional strategies, his fraught interactions with the British state, and the ambivalent public reaction to his contraptions provides insight into how scientific authority was acquired and lost in this period.

Dark Energy and Electromagnetism

The study addresses the following question: what is the source of the Dark Energy? The study provides sound argumentations that Electromagnetic Waves, from separate sources, can consolidate, even though such consolidations seem to embed paradoxes. The study also proposes a physical experiment which might implement consolidations of Electromagnetic Waves, from separate sources. In addition to the above, the study also addresses paradoxes related to the Mutual Annihilation and the Pair Production processes. The study proposes a resolution for all these paradoxes which also concludes that most of the Dark Energy might be related to Electromagnetism and that the Electric Charge is also a form of Energy.

Basel Bank Limiting Policies as Foucauldian Power/Knowledge: Risk as Assemblages, The Case of Basel Bank Limiting Policies as Discourses

I intend to write about Basel bank's limiting technologies from the point of view of trust, coming from the fact that banks have to adjust their risk understanding tools and test them constantly. It is not always known what exactly causes a risk. I am interested in risk-understanding technologies which do not govern this in advance but only require passing certain risk tests. Therefore, I will research the idea of Basel’s bank limiting technologies as assemblages that want connections only with other specified assemblages. For example, certain risk levels must be adjusted to form a harmonious whole that passes these tests. I will argue that by understanding Basel’s bank limiting technologies through the theory of assemblages, it is possible to spell out the notion of biopower in the assemblage that has only a purely economic or statistical status. This biopower means the ability of a certain bank to control its assessments by estimating those same forms in different diagrams. I will work with the condition that there are no rules as to how to control the risks, only of what the abstract risk levels must be. This is based on the standpoint of the assemblage theory's idea that certain particles can be removed because the particles are tied to the whole. The point of this analysis is to show that trust does not lie in mutual understanding, but rather in the abstract risk levels and certain tests that the bank has to go through. Trust is not created by doing something that would restrict the bank’s ability to act by itself, but by making sure that the governor knows that the bank is in trouble if it does not keep risk at a certain level compared to rules that would govern how the bank has to act. It does this by using a technique that ties the bank’s risks to the tools with which it normally functions. Therefore, it cannot cheat the system by using different tools to profit from excessive risks. This system of certain risk technologies tied to both sides of the bank’s infrastructure is called M.A.D. (Mutually Assured Destruction) because it does not show one side without the other. Therefore, biopower is applied to the bank’s risk technologies by making sure that bank knows how to work for its well-being and at the same time also ensures that it works for the general good. This sounds a lot like an invisible hand that makes individuals’ actions beneficial to the whole community. This idea seems to develop more instrumentally in this argument, but there is the same “clever lie” behind it.

Gambling the World: The Cuban Missile Crisis Revisited

From North Korea to Ukraine to Iran, the spectre of nuclear war continues to loom over global affairs. In his timely history Nuclear Folly, Harvard historian Serhii Plokhy takes a fresh and intentionally international look at one of the most fraught moments of the Cold War: the Cuban Missile Crisis. Contrary to the conventional view that US president John F. Kennedy brilliantly out-foxed his inept Soviet counterpart, Nikita Khrushchev, Plokhy posits that both sides repeatedly erred and misread each other – greatly increasing the likelihood of mutual annihilation. Plokhy draws lessons from the crisis for contemporary decision-makers, noting that the power to wield nuclear weapons still resides in a small number of hands.

M.A.D. AGAIN? Shift of the Term M.A.D. to the Cyber Domain

The article introduces a new meaning of the acronym M.A.D. (Mutually Assured Destruction) in the field of security. From the original connection with nuclear issues, its use is moving to the area of cyberspace. The text introduces the basic division of domains important for human activities. It explains their importance in terms of undeniable usability and availability for mankind, at the same time, it draws attention to their vulnerability and the need to ensure their protection. It deals in more details with the new fifth domain – cyberspace. In this context, security threats are mentioned and some legal aspects are indicated.