arXiv subjects

M. A. Valuyan

Publications and source records attributed to M. A. Valuyan.

16 recordsLinked to original sources

arXiv2026

Radiative Correction to the Casimir Energy for Massive Scalar Field in The Network

In this paper, we compute the leading-order and first-order radiative corrections to the Casimir energy of a massive Lorentz-violating scalar field governed by a $ϕ^4$ interaction on a network. For simplicity, the network is chosen to consist of three edges connected at a single central junction, with the scalar field defined in 1+1 dimensions on each edge. Dirichlet boundary conditions are imposed at the outer ends of the edges, thereby confining the field on the network. Beyond addressing the massive case of a Lorentz-violating scalar field, a key novelty of this work lies in the calculation of the radiative corrections to the Casimir energy using position-dependent counterterms. These counterterms emerge from a systematic renormalization program that consistently incorporates the effects of boundary conditions into the renormalization procedure. To eliminate divergences arising from vacuum energy contributions, we employ the box subtraction scheme in conjunction with cutoff regularization. Our results show that both the leading-order and first-order Casimir energies are negative, regardless of the presence or absence of Lorentz-violating effects, and are in agreement with general physical expectations.

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arXiv2025

One-Loop Correction to the Casimir Energy in Lorentz-Violating $ϕ^4$ Theory with Rough Membrane Boundaries

In this paper, we calculate the radiative correction to the Casimir energy for both massive and massless Lorentz-violating scalar fields confined between two membranes with rough surfaces in a 3+1 dimensional spacetime. The computations are performed for four types of boundary conditions: Dirichlet, Neumann, Periodic, and Mixed. A crucial element of our approach involves the use of position-dependent counterterms to incorporate the influence of boundaries within the renormalization program. To manage the divergences that emerge in the Casimir energy calculations, we apply the Box Subtraction Scheme (BSS) along with the cutoff regularization technique. We present and discuss results for various degrees of membrane roughness, emphasizing the consistency of our findings with theoretical expectations.

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arXiv2024

Æther Coupling Effects on Casimir Energy for Self-Interacting Scalar Field within Extra Dimension

This paper presents comprehensive calculations for thermal and first-order radiative corrections to the Casimir energy in systems involving self-interacting massive and massless scalar fields coupled with æther in a fifth compact dimension. The method used to compute the radiative correction to the Casimir energy differs from conventional approaches by applying a unique renormalization scheme that is consistent with specific boundary conditions or backgrounds. Despite this divergence from conventional methodologies, our results demonstrate consistency within established physical limits. Furthermore, employing a toy model, we calculated the total Casimir energy density in the bulk, taking into account both thermal and radiative corrections. We also provide a thorough characterization of the total Casimir energy density in the compact dimension, detailing its magnitude and sign using graphical representations and quantitative data.

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arXiv2024

Casimir Energy for Lorentz-Violating Scalar Field with Helical Boundary Condition in d Spatial Dimensions

Delving into spring-like helical configurations, such as DNA within our cells, motivates physicists to inquire about the effects of such structures in the realm of quantum field theory, specifically unraveling their manifestation of effectiveness in Casimir energy. To explore this, we initiated our investigation with the Casimir effect and proceeded to calculate the Casimir energy, along with its thermal and radiative corrections, for massive and massless Lorentz-violating scalar fields across $d+1$ dimensional space-time. Adhering to the principle that the renormalization program should be consistent with the boundary conditions applied to the quantum fields was paramount. Accordingly, one-loop correction to the Casimir energy for both massive and massless scalar fields under helical boundary conditions by employing a position-dependent counterterm was performed. Our results, spanning across spatial dimensions, exhibited convergence and coherence with established physical grounds. Additionally, we presented the Casimir energy density using graphical plots for systems featuring time-like and space-like Lorentz violations across all spatial dimensions, followed by a comprehensive discussion of the obtained results.

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arXiv2021

One-Loop Correction to The Casimir Energy in Lifshitz-Like Theory

In the present article, Radiative Correction (RC) to the Casimir energy was computed for the self-interacting massive/massless Lifshitz-like scalar field, confined between a pair of plates with Dirichlet and Mixed boundary conditions in $3+1$ dimensions. Moreover, using the results obtained for the Dirichlet Casimir energy, the RC to the Casimir energy for Periodic and Neumann boundary conditions were also draw outed. To renormalize the bare parameters of the Lagrangian, a systematic perturbation expansion was used in which the counterterms were automatically obtained in a position-dependent manner. In our view, the position dependency of the counterterm was allowed, since it reflected the effects of the boundary condition imposed or the background space in the problem. All the answers obtained for the Casimir energy were consistent with well-known physical expects. In the language of graphs, the Casimir energy for the massive Lifshitz-like scalar field confined with four boundary conditions (Dirichlet, Neumann, Mixed, and Periodic) was also compared to each other, and as a concluding remark, the sign and magnitude of their values were discussed.

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arXiv2020

Radiative Correction to The Casimir Energy with Mixed Boundary Condition in 2+1 Dimensions

In the present study, the zero- and first-order radiative correction to the Casimir energy for the massive and massless scalar field confined with mixed (Neumann-Dirichlet) boundary condition between two parallel lines in 2+1 dimensions for the self-interacting $ϕ^4$ theory was computed. The main point in this study is the use of a special program to renormalize the bare parameters of the Lagrangian. The counterterm used in the renormalization program, which was obtained systematically position-dependent, is consistent with the boundary condition imposed on the quantum field. To regularize and remove infinities in the calculation process of the Casimir energy, the Box Subtraction Scheme as a regularization technique was used. In this scheme, two similar configurations are usually introduced, and the vacuum energies of these two configurations in proper limits are subtracted from each other. The final answer for the problem is finite and consistent with the expected physical basis. We also compared the new result of this paper to the previously reported results in the zero- and first-order radiative correction to the Casimir energy of scalar field in two spatial dimensions with Periodic, Dirichlet, and Neumann boundary conditions. Finally, all aspects of this comparison were discussed.

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arXiv2020

Radiative Correction to the Casimir Energy for Lorentz-violating Scalar Field in d+1 Dimensions

The renormalization program in every renormalized theory should be run consistently with the type of boundary condition imposed on quantum fields. To maintain this consistency, the counterterms usually appear in the position-dependent form. In the present study, using such counterterms, we calculated the radiative correction to the Casimir energy for massive and massless Lorentz-violating scalar field constrained with Dirichlet boundary condition between two parallel plates in d spatial dimensions. In the calculation procedure, to remove infinities appearing in the vacuum energies, the box subtraction scheme supplemented by the cutoff regularization technique and analytic continuation technique were employed. Normally, in the box subtraction scheme, two similar configurations are defined and their vacuum energies are subtracted from each other in the appropriate limits. Our final results regarding all spatial dimensions were convergent and consistent with the expected physical basis. We further plotted the Casimir energy density for the time-like and space-like Lorentz-violating systems in a number of odd and even dimensions; multiple aspects of the obtained results were ultimately discussed.

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arXiv2019

Radiative Correction of the Casimir Energy for the Scalar Field with the Mixed Boundary Condition in 3 + 1 Dimensions

In the present study, the zeroth- and first-order radiative correction of the Casimir energy for massive and massless scalar fields, confined with mixed boundary conditions (Dirichlet- Neumann) between two parallel plates in $ϕ^4$ theory, were computed. Two issues in performing calculations in this work are essential: first, to renormalize the bare parameters of the problem, a systematic method was used, which allows all influences from the boundary conditions to be imported in all elements of the renormalization program. This idea yields our counterterms appearing in the renormalization program to be position-dependent. Using the box subtraction scheme as a regularization technique is the other noteworthy point in the calculation. In this scheme, by subtracting the vacuum energies of two similar configurations from each other, regularizing divergent expressions and their removal process were significantly facilitated. All the obtained answers for the Casimir energy with the mixed boundary condition were consistent with well-known physical grounds. We also compared the Casimir energy for the massive scalar field confined with four types of boundary conditions (Dirichlet, Neumann, a mix of them and Periodic) in 3+1 dimensions with each other, and the sign and magnitude of their values were discussed.

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arXiv2018

Casimir energy calculation for massive scalar field on spherical surfaces: an alternative approach

In this study, the Casimir energy for massive scalar field with periodic boundary condition was calculated on spherical surfaces with $S^1$, $S^2$ and $S^3$ topologies. To obtain the Casimir energy on spherical surface, the contribution of the vacuum energy of Minkowski space is usually subtracted from that of the original system. In large mass limit for surface $S^2$; however, some divergences would eventually remain in the obtained result. To remove these remaining divergences, a secondary renormalization program was manually performed. In the present work, a direct approach for calculation of the Casimir energy has been introduced. In this approach, two similar configurations were considered and then the vacuum energies of these configurations were subtracted from each other. This method provides more physical meaning respect to the other common methods. Additionally, in large mass limit for surface $S^2$, it provides a situation in which the second renormalization program is automatically conducted in the calculation procedure, and there was no need to do that anymore manually. Finally, by plotting the obtained values for the Casimir energy of the topologies and investigating their appropriate limits, the logic agreement between the results of our scheme and those of previous studies were discussed.

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arXiv2018

The Dirichlet Casimir Energy For ϕ^4 Theory in a Rectangular Waveguide

In this paper, we presented the zero- and first-order radiative corrections to the Casimir energy for a massive scalar field confined with Dirichlet boundary condition in an open-ended rectangular waveguide. In the calculation procedure, we applied a systematic renormalization program that allows all influences imposed by dominant boundary conditions in a problem be automatically reflected in the counterterms, leading the counterterms to be obtained in a position-dependent manner. To remove the appeared divergences in the computation task, the Box Subtraction Scheme as a regularization technique was used. In this regularization technique, usually, two similar configurations were introduced. Then, to find the Casimir energy, the zero point energies of these two configurations were subtracted from each other via defining appropriate limits. In the present work, first, the leading-order Casimir energy for the massive scalar field in a waveguide is briefly presented. Next, by applying this renormalization and regularization procedures, the first-order radiative correction to the Casimir energy in the waveguide is calculated. Finally, all the necessary limits of the obtained answers for massive and massless cases are computed and the consistency of the obtained results are discussed.

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arXiv2018

The Casimir Energy For Scalar Field With Mixed Boundary Condition

In the present study, the first-order radiative correction to the Casimir energy for massive and massless scalar fields confined with mixed boundary conditions (Dirichlet-Neumann) between two points in ϕ^4 theory was computed. Two issues in performing the calculations in this work are essential: to renormalize the bare parameters of the problem, a systematic method was employed, allowing all influences from the boundary conditions to be imported in all elements of the renormalization program. This idea yields our counterterms appeared in the renormalization program to be position-dependent. Using the Box Subtraction Scheme (BSS) as a regularization technique is the other noteworthy point in the calculation. In this scheme, by subtracting the vacuum energies of two similar configurations from each other, regularizing divergent expressions and their removal process were significantly facilitated. All the obtained answers for the Casimir energy with the mixed boundary condition were consistent with well-known physical grounds. We also compared the Casimir energy for massive scalar field confined with four types of boundary conditions (Dirichlet, Neumann, mixed of them and Periodic) in 1+1 dimensions with each other, and the sign and magnitude of their values were discussed.

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arXiv2018

The Dirichlet Casimir Energy for $ϕ^4$ Theory in a Rectangle

In this article, we present the zero and first-order radiative correction to the Dirichlet Casimir energy for massive and massless scalar field confined in a rectangle. This calculation procedure was conducted in two spatial dimensions and for the case of the first-order correction term is new. The renormalization program that we have used in this work, allows all influences from the dominant boundary conditions (e.g. the Dirichlet boundary condition) be automatically reflected in the counterterms. This permission usually makes the counterterms position-dependent. Along with the renormalization program, a supplementary regularization technique was performed in this work. In this regularization technique, that we have named Box Subtraction Scheme (BSS), two similar configurations were introduced and the zero point energies of these two configurations were subtracted from each other using appropriate limits. This regularization procedure makes the usage of any analytic continuation techniques unnecessary. In the present work, first, we briefly present calculation of the leading order Casimir energy for the massive scalar field in a rectangle via BSS. Next, the first order correction to the Casimir energy is calculated by applying the mentioned renormalization and regularization procedures. Finally, all the necessary limits of obtained answers for both massive and massless cases are discussed.

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arXiv2017

Radiative Correction to the Casimir Energy for Massive Scalar Field on a Spherical Surface

In this paper, the first order radiative correction to the Casimir energy for a massive scalar field in the $ϕ^4$ theory on a spherical surface with $S^2$ topology was calculated. In common methods for calculating the radiative correction to the Casimir energy, the counter-terms related to free theory are used. However, in this study, by using a systematic perturbation expansion, the obtained counter-terms in renormalization program were automatically position-dependent. We maintained that this dependency was permitted, reflecting the effects of the boundary conditions imposed or background space in the problem. Additionally, along with the renormalization program, a supplementary regularization technique that we named Box Subtraction Scheme (BSS) was performed. This scheme presents a useful method for the regularization of divergences, providing a situation that the infinities would be removed spontaneously without any ambiguity. Analysis of the necessary limits of the obtained results for the Casimir energy of the massive and massless scalar field confirmed the appropriate and reasonable consistency of the answers.

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arXiv2012

Casimir Energy For a Massive Dirac Field in One Spatial Dimension: A Direct Approach

In this paper we calculate the Casimir energy for a massive fermionic field confined between two points in one spatial dimension, with the MIT Bag Model boundary condition. We compute the Casimir energy directly by summing over the allowed modes. The method that we use is based on the Boyer's method, and there will be no need to resort to any analytic continuation techniques. We explicitly show the graph of the Casimir energy as a function of the distance between the points and the mass of the fermionic field. We also present a rigorous derivation of the MIT Bag Model boundary condition.

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arXiv2009

Radiative Correction to the Dirichlet Casimir Energy for $λϕ^{4}$ Theory in Two Spatial Dimensions

In this paper, we calculate the next to the leading order Casimir energy for real massive and massless scalar fields within $λϕ^{4}$ theory, confined between two parallel plates with the Dirichlet boundary condition in two spatial dimensions. Our results are finite in both cases, in sharp contrast to the infinite result reported previously for the massless case. In this paper we use a renormalization procedure introduced earlier, which naturally incorporates the boundary conditions. As a result our radiative correction term is different from the previously calculated value. We further use a regularization procedure which help us to obtain the finite results without resorting to any analytic continuation techniques.

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arXiv2009

Dirichlet Casimir Energy for a Scalar Field in a Sphere: An Alternative Method

In this paper we compute the leading order of the Casimir energy for a free massless scalar field confined in a sphere in three spatial dimensions, with the Dirichlet boundary condition. When one tabulates all of the reported values of the Casimir energies for two closed geometries, cubical and spherical, in different space-time dimensions and with different boundary conditions, one observes a complicated pattern of signs. This pattern shows that the Casimir energy depends crucially on the details of the geometry, the number of the spatial dimensions, and the boundary conditions. The dependence of the \emph{sign} of the Casimir energy on the details of the geometry, for a fixed spatial dimensions and boundary conditions has been a surprise to us and this is our main motivation for doing the calculations presented in this paper. Moreover, all of the calculations for spherical geometries include the use of numerical methods combined with intricate analytic continuations to handle many different sorts of divergences which naturally appear in this category of problems. The presence of divergences is always a source of concern about the accuracy of the numerical results. Our approach also includes numerical methods, and is based on Boyer's method for calculating the electromagnetic Casimir energy in a perfectly conducting sphere. This method, however, requires the least amount of analytic continuations. The value that we obtain confirms the previously established result.

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