Pith. sign in

REVIEW 2 major objections 4 minor 51 references

Electromagnetic Boundary Conditions for Space--time Interfaces

T0 review · 2 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read Every causal, linear electromagnetic boundary condition is a special case of one spacetime formula.

desk verdict A genuinely useful tensorial unification of spacetime boundary conditions, but the abstract's 'most general' claim exceeds the theorem, which needs boundary-locality and finite maximal order. read the letter →

arxiv 2507.05889 v1 pith:DSIDOSAK submitted 2025-07-08 physics.optics physics.class-ph

classification physics.opticsphysics.class-ph
keywords electromagneticboundaryconditionsspace-timeinterfacestemporalboundariesmetasurfacesspatialdispersioncausality4-dimensionalspacetimeformalism
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper claims that all physically admissible linear boundary conditions connecting electromagnetic fields across a space–time interface—static, purely temporal, uniformly moving, accelerating, or implemented as a thin metasurface—are special cases of a single formula, Eq. (28). The formula lives in 4-dimensional spacetime: a boundary is a 3-dimensional hypersurface $\Sigma$, and the condition relates the field tensors $F_{\mu\nu}$ and $H_{\mu\nu}$ on the two sides through kernels integrated over the part of $\Sigma$ causally connected to each boundary point. The authors prove (Theorem 1) that any boundary condition that is linear, causal, local to the boundary with differential dependence, and has a finite maximal order must be of this form. If true, this unifies a literature that currently treats spatial, temporal, and moving interfaces case by case, and gives a recipe for writing down boundary conditions for new space–time metasurfaces, including dispersive ones.

What carries the argument

The central object is Eq. (28), a kernel-integral boundary condition written in coordinates $(u^1,u^2,u^3,z)$ adapted to the hypersurface $\Sigma$ ($z=0$). The kernels $\kappa$ are distributions in the surface coordinates $u'$, so local conditions arise as delta functions while in-plane dispersion appears as convolutions; causality restricts all integrations to the causal part $J^\Sigma(u)$ of the boundary. The proof machinery is the order extraction: a boundary condition has order $k$ if it vanishes whenever the fields are multiplied by $z^{k+1}$, and the extraction formula (39) recovers the kernels by applying the remainder to bump-function test fields. Taylor expansion in $z$ then reduces any admissible condition to the finite sum of normal derivatives appearing in Eq. (28).

What would settle it

Take a thin slab of thickness $d$ whose effective response is a smooth kernel $K(z-z')$ in the normal coordinate, so the boundary relation is an integral over $z'$ rather than a finite sum of derivatives at $z=0$. If the scattering from such a slab cannot be matched by Eq. (28) for any finite $k$, then the maximal-order assumption of Theorem 1 is violated and the claimed generality fails.

Watch

Extended reading notes

Core claim

The paper's central claim is that Eq. (28) is the most general electromagnetic boundary condition that can connect the fields $F_{\mu\nu}$ and $H_{\mu\nu}$ across an arbitrary 3-dimensional space-time hypersurface $\Sigma$ while remaining linear, causal, and local to the boundary. In adapted coordinates $(u^1,u^2,u^3,z)$ with $\Sigma$ at $z=0$, the condition is a sum over $r=0,\dotsc,k$ of integrals over the causal part $J^\Sigma(u)$ of $\Sigma$, with distribution kernels $\kappa$ multiplying the $r$-th normal derivatives of $F$ and $H$ evaluated on either side. Theorem 1 proves that any set of boundary conditions satisfying linearity, causality, boundary-locality with differential dependence, and a finite maximal order $k$ must take this form; the proof expands fields in a Taylor series in $z$, uses the maximal-order condition to discard the remainder, and uses causality to restrict the kernels' support to $J^\Sigma(u)$. The standard spatial conditions (continuity of tangential $E$, $H$ and normal $B$, $D$), the temporal conditions (continuity of $B$ and $D$), and the moving-boundary conditions (continuity of $E_\parallel + V\times B_\parallel$ and $H_\parallel - V\times D_\parallel$) are all recovered as special cases, as are additional boundary conditions for spatially and temporally dispersive media.

Load-bearing premise

The theorem assumes each admissible boundary condition has a finite 'maximal order': it depends only on the fields and finitely many of their derivatives right at the surface, so multiplying the fields by a sufficiently high power of the normal coordinate makes the condition automatically satisfied; boundary conditions that are nonlocal through the thickness of the sheet fall outside the claimed generality.

Editorial extensions

If this is right

  • Any linear, causal, local boundary condition on a static surface, a purely temporal interface, a uniformly moving boundary, or an accelerating boundary can be expressed in the single form (28), so results derived for one interface type can be translated to the others.
  • New boundary conditions for metasurfaces and space-time interfaces can be specified by choosing the number $m$ of conditions, the order $k$, and the kernels $\kappa$, which is a concrete design recipe rather than a case-by-case calculation.
  • Spatial and temporal dispersion are handled uniformly: additional boundary conditions from bulk dispersive media enter as extra rows $A$, while in-plane nonlocality (the sheet susceptibility) enters through the convolution kernels, including the causal restriction to $J^\Sigma(u)$.
  • Prescribed surface currents and charges can be added to the right-hand side of (28), giving inhomogeneous boundary conditions that generalize Dirichlet and von Neumann conditions to higher order and to extended dependence within the boundary.
  • The framework opens the way to treat space-time corners and wedges, where the normal is discontinuous and conventional conditions can contradict one another.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • By the theorem's own logic, any candidate boundary condition that cannot be written as Eq. (28) must violate at least one of the axioms—linearity, causality, boundary-locality with differential dependence, or finite maximal order. This gives a practical test: a proposed boundary condition that fails to fit the form is either nonlocal through the sheet, acausal, or nonlinear, rather than an overloo
  • The maximal-order assumption is the place where real metasurfaces could escape the classification: a sheet whose thickness is not negligible relative to the wavelength will have an effective response involving integrals across the sheet, which is not equivalent to finitely many normal derivatives. Extending Eq. (28) to such kernels would be the natural next step.
  • The restriction of the integration domain to $J^\Sigma(u)$ turns causality into a support condition on the kernels. This suggests a concrete way to audit published space-time boundary conditions: check whether the kernel support lies inside $J^\Sigma(u)$; if not, the condition permits surface waves to influence a point from outside its causal past.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 4 minor

Summary. The paper proposes a general family of electromagnetic boundary conditions on arbitrary space–time hypersurfaces, expressed in Eq. (28) as integral-kernel relations over the causal past J^Σ(u) of each boundary point, involving the fields and their normal derivatives up to order k on either side of the interface. Section II reviews standard spatial and temporal boundary conditions, moving-boundary generalizations, and dispersive examples such as sheet transition conditions. Section III states the general form, shows how known cases are recovered, and presents Theorem 1, which claims that any set of boundary conditions that is linear, causal, local to Σ with differential dependence, and of finite maximal order, must be of the form (28). The paper also discusses extraction of the kernels and sketches extensions to nonlinear conditions.

Significance. If Theorem 1 is accepted for the class of local, finite-order boundary conditions, the paper provides a useful unifying four-dimensional framework that recovers the standard spatial, temporal, and moving-boundary conditions as special cases and accommodates spatially and temporally dispersive interfaces. The tensorial formulation is clean, the recovery of known results is demonstrated in detail, and the proof is largely checkable step by step. The main caveat is that the advertised 'most general' claim in the abstract and introduction exceeds what the theorem actually proves, because the theorem imposes substantive additional assumptions (locality to Σ, finite maximal order) that are not consequences of linearity and causality alone. With the claim properly qualified, the paper is a solid contribution to the systematic treatment of space–time interfaces.

major comments (2)
  1. [Abstract and Section III.B, Theorem 1] The paper's central claim that Eq. (28) gives the most general boundary conditions consistent with causality and linearity is not supported by Theorem 1. The theorem assumes, in addition to linearity and causality, that the boundary conditions 'depend only on the fields on the boundary and their derivatives' and that there is a finite maximal order k. These assumptions are used decisively in the proof: the Taylor expansion of F^I about z=0 discards the remainder z^{k+1}E precisely because the maximal-order assumption forces D_A[z^{k+1}E]=0. Without a finite maximal order, the remainder contributes and the representation (28), which samples only ∂_z^r F at z=0 for r≤k, does not follow. Similarly, a linear causal condition such as ∫_{-ε}^{ε} w(z)E_x(z)dz=0, modeling a finite-thickness nonlocal sheet, or an infinite-order local condition such as exp(a∂_z)E_x|_{z=0}=0, would escape Eq. (28). The abstract and the introduction should state the full set of assumptions explicitly, and the body should acknowledge that nonlocal-in-normal and infinite-order conditions are not covered. This is not a fatal flaw of the theorem itself, but the unqualified 'most general' claim is currently inaccurate.
  2. [Section III.B, proof of Theorem 1] The proof contains an unproved step: after representing D^{FI}_{Ar}(u) as an integral over Σ, it says 'from causality we have to restrict the domain of the integral to J^Σ(u)'. Since the conclusion (28) includes the causality domain J^Σ(u) as part of the representation, this restriction is load-bearing. However, the paper does not prove that causality implies the kernel has support in J^Σ(u); it simply asserts this. The authors should either provide a distributional support argument showing that the kernel vanishes outside the causal past, or state explicitly that support in J^Σ(u) is part of the causality assumption. As written, the theorem's conclusion does not fully follow from the listed axioms.
minor comments (4)
  1. [Figure 3 caption, Section II.C] The phrase 'There has to be confusion in the language when talking about boundaries' is unclear and should be rephrased to describe the terminology issue more precisely.
  2. [Section II.D, paragraph on adapted coordinates] The sentence 'We write u = (u1,u2,u3,u4) as the three surface coordinates u = (u1,u2,u3), plus u4 which is the coordinate normal to the surface' appears to contain a typo: 'three surface coordinates' should be 'four coordinates' or the notation should be clarified to distinguish the full coordinate tuple from the three surface coordinates.
  3. [References, Ref. [40]] Reference [40] lists the arXiv identifier as 'arxiv:410.23291v1', which appears to be a typo; please verify and correct the number.
  4. [Section II.E, Eq. (26)] The multi-index notation s=(s1,s2,s3,s4) is introduced but the text immediately afterward says 'the vector s = (s1, s2, s3)' in the explanation; this inconsistency should be corrected so that the normal derivative order s4 is clearly included.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: Theorem 1 is a representation theorem proved from explicit assumptions; the abstract's 'most general' phrasing overstates the theorem's scope, but no claim reduces to its own inputs.

full rationale

The paper's central claim is not arrived at by fitting or by self-citation. Theorem 1 (Section III.B) states: 'Given a set of BCs which are linear, causal, local to Σ with differential dependence and a maximal order... Then these BCs are given by equation (28).' The proof starts from the assumed distribution D_A(u), uses linearity to split it into four functionals, Taylor-expands each field in the normal coordinate z, discards the z^{k+1} remainder by the maximal-order assumption, and applies the distribution-kernel representation on the 3D boundary; causality then restricts the kernel's support to J^Σ(u). Every step is justified by the explicitly listed assumptions, not by Eq. (28). The 'maximal order' and 'differential dependence' assumptions do the work of excluding nonlocal-in-normal and infinite-order BCs; the abstract's phrase 'most general conditions consistent with causality and linearity' therefore overstates the theorem's scope, since Theorem 1 also assumes boundary-locality in the normal direction and a finite maximal order. That is an overclaim or scope gap, not a circular reduction: a condition such as ∫ w(z)E_x(z)dz=0 would escape Eq. (28), but that does not mean Eq. (28) was assumed. The self-citations [27] (Harwood et al., including Horsley) and [37] (Gratus et al.) are used for background points only ('synthetic motion' and the temporal-dispersion ABC observation), not to justify the uniqueness or generality of Eq. (28). There is no imported uniqueness theorem, no fitted parameter renamed as prediction, and no ansatz smuggled in via citation. Thus the derivation chain is self-contained, and the paper receives a zero circularity score.

Assumptions & free parameters 0 free parameters · 6 assumptions · 0 invented entities

The paper's central theorem rests on the axioms listed in Section III.B: linearity, causality, locality to the boundary, differential dependence, maximal order, and the existence of a finite set of distributional remainder functions. These are reasonable but not derived from Maxwell's equations; the 'most general' result is conditional on them. There are no fitted parameters or invented physical entities. The free parameters are all contained in the unspecified kernels kappa, which are part of the general form rather than fitted to data.

assumptions (6)
  • domain assumption Linearity of boundary conditions: sums and scalar multiples of solutions are solutions.
    Stated in Section III.B as a necessary condition for the boundary conditions to be general. It is not derived from Maxwell's equations but is a standard modeling assumption for linear media.
  • domain assumption Causality: information about the field on one side of the boundary does not travel faster than light, implemented by restricting the integral in Eq. (28) to the causal past J^Σ(u).
    Introduced in Section III.B and used in the proof of Theorem 1 to restrict the domain of integration. This is a physical assumption imposed on the boundary conditions, not proved.
  • domain assumption Locality to the boundary: boundary conditions depend only on the fields on the boundary and a finite number of derivatives evaluated there.
    Stated in Section III.B as a requirement for something to be a boundary condition. This assumption excludes nonlocal-in-normal-direction conditions that might depend on fields away from the surface.
  • domain assumption Maximal order: there exists a positive integer k such that all fields multiplied by z^{k+1} (where z is the normal coordinate) satisfy the boundary conditions.
    Introduced in Section III.B as a technical condition needed for the Taylor expansion proof. It is not derived from linearity and causality and may fail for certain nonlocal or infinite-order conditions.
  • domain assumption Existence of a finite set of distributions D_A(u) representing the boundary conditions.
    Assumed in Theorem 1 as the starting point of the proof. It is a broad but not fully general representation, since not all conceivable boundary conditions may be expressed this way.
  • standard math Standard tensor calculus and the 4D form of Maxwell's equations.
    The framework uses F_mu_nu and H_mu_nu tensors and adapted coordinate systems, which are standard in classical electromagnetism and differential geometry.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Electromagnetic Boundary Conditions for Space--time Interfaces." pith.science (2026). https://pith.science/paper/DSIDOSAK

@misc{pith2026250705889,
  author       = {Pith},
  title        = {Pith review of: Electromagnetic Boundary Conditions for Space--time Interfaces},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DSIDOSAK}},
  note         = {Machine review of arXiv:2507.05889}
}
read the original abstract

We give a general family of electromagnetic boundary conditions applicable to arbitrary space--time interfaces between electromagnetic media, which include the known space--only and time--only boundary conditions as special cases. These boundary conditions describe a broad class of electromagnetic interfaces, including surfaces in arbitrary motion, ultra-thin (metasurface) media, and cases where the media on one or both sides of the boundary can be both spatially and temporally dispersive. Our approach utilizes 4-dimensional spacetime and addresses the question of how, and in what ways, an electromagnetic field may be connected across a 3-dimensional hypersurface. We show that our proposed boundary conditions are the most general conditions consistent with causality and linearity.

Figures

Figures reproduced from arXiv: 2507.05889 by the authors.

Figure 1
Figure 1. FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2: Even though much of the boundary depicted lies in the past light cone of [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p007_3.png] view at source ↗
Figures from the paper (1 more)
Figure 4
Figure 4. Figure 4: FIG. 4 [PITH_FULL_IMAGE:figures/full_fig_p013_4.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

51 extracted references · 49 canonical work pages

  1. [1]

    Thus the continuity of the x–component of the polarization P I x = P I I x can be included in Eq. (28) (here A = 7) κFI 70 µν(u, u′) = κFI I 70 µν(u, u′) = − ϵ0c 2 (δµ 0 δν 1 − δν 0 δµ 1 ) δ(u − u′) and κHI 70 µν(u, u′) = κHI I 70 µν(u, u′) = 1 2c (δµ 2 δν 3 − δν 2 δµ 3 ) δ(u − u′). (31) If, in addition the time derivative of the polarization is continuou...

  2. [2]

    Achouri, M

    K. Achouri, M. A. Salem, and C. Caloz, General metasurface synthesis based on susceptibility tensors, IEEE Trans. Ant. Prop. 63, 2977 (2015)

  3. [3]

    These topics will form the focus of future research

    F I µν(u′ 1, 0)F I µν(u′ 2, 0)F I µν(u′ 3, 0) (43) and similarly for higher derivatives. These topics will form the focus of future research. 23 Author contributions JG conceptualised the ideas produced the first draft. All authors contributed equally to writing the manuscript. F unding JG acknowledges support from STFC and the Cockcroft institute (ST/V00...

  4. [4]

    T. G. Mackay and A. Lakhtakia, Electromagnetic Anisotropy and Bianisotropy: A Field Guide (World Scientific, 2019)

  5. [5]

    B. A. Munk, Frequency Selective Surfaces, Theory and Design (Wiley, 2005)

  6. [6]

    Galiffi, R

    E. Galiffi, R. Tirole, S. Yin, H. Li, S. Vezzoli, P. A. Huidobro, M. G. Silveirinha, R. Sapienza, A. Al´ u, and J. B. Pendry, Photonics of time-varying media, Advanced Photonics , 014002 (2022). 24

  7. [7]

    Taravati and G

    S. Taravati and G. V. Eleftheriades, Space-time metasurfaces: Analysis, design and applica- tions, in 2021 15th European Conference on Antennas and Propagation (EuCAP) (2021) pp. 1–5

  8. [8]

    H. T. Chen, A. J. Taylor, and N. Yu, A review of metasurfaces: physics and applications, Rep. Prog. Phys. 79, 076401 (2016)

Show all 51 references
  1. [9]

    Assouar, B

    B. Assouar, B. Liang, Y. Wu, Y. Li, J.-C. Cheng, and Y. Jing, Acoustic metasurfaces, Nature Reviews Materials 3, 460 (2018)

  2. [10]

    Chen, Y.-S

    A.-L. Chen, Y.-S. Wang, Y.-F. Wang, H.-T. Zhou, and S.-M. Yuan, Design of Acoustic/Elastic Phase Gradient Metasurfaces: Principles, Functional Elements, Tunability, and Coding, Ap- plied Mechanics Reviews 74, 020801 (2022)

  3. [11]

    S. A. Tretyakov, Analytical Modeling in Applied Electromagnetics (Artech House, 2003)

  4. [12]

    J. Wang, L. Qin, and W. Xu, Flexible and high precision thermal metasurface, Communica- tions Materials 2, 89 (2021)

  5. [13]

    Achouri and C

    K. Achouri and C. Caloz, Electromagnetic Metasurfaces: Theory and Applications (John Wiley and Sons, 2021)

  6. [14]

    C. J. Holloway, A. Dienstfrey, E. F. Kuester, J. F. O’Hara, A. K. Azad, and A. J. Taylor, A discussion on the interpretation and characterization of metafilms/metasurfaces: The two- dimensional equivalent of metamaterials, Metamaterials 3, 100 (2009)

  7. [15]

    K. Wu, P. Coquet, Q. J. Wang, and P. Genevet, Modelling of free-form conformal metasurfaces, Nat. Comm. 9, 3494 (2018)

  8. [16]

    Lebbe, A

    N. Lebbe, A. Maurel, and K. Pham, Homogenized transition conditions for plasmonic meta- surfaces, Phys. Rev. B 107, 085124 (2023)

  9. [17]

    S. Maci, G. Minatti, M. Casaletti, and M. Bosiljevac, Metasurfing: Addressing waves on impenetrable metasurfaces, IEEE Antennas and Wireless Propagation Letters10, 1499 (2011)

  10. [18]

    Zalu˘ ski, A

    D. Zalu˘ ski, A. Grbic, and S. Hrabar, Analytical and experimental characterization of meta- surfaces with normal polarizability, Phys. Rev. B 93, 155156 (2016)

  11. [19]

    T. B. A. Senior and J. L. Volakis, Approximate boundary conditions in electromagnetics (IEE Publication Series, 1995)

  12. [20]

    Fleury, D

    R. Fleury, D. L. Sounas, and A. Al´ u’, Negative refraction and planar focusing based on parity- time symmetric metasurfaces, Phys. Rev. Lett. 113, 023903 (2014)

  13. [21]

    Gustafson and T

    K. Gustafson and T. Abe, The third boundary condition—was it Robin’s?, Mathematical Intelligencer 20, 63 (1998). 25

  14. [22]

    I. V. Lindell and A. Sihvola, Electromagnetic wave reflection from boundaries defined by general linear and local conditions, IEEE Transactions on Antennas and Propagation 65, 4656 (2017)

  15. [23]

    but with the velocity evaluated at a fixed time. This is the expected result, applying 12 space time (u, 0) z spatial boundary space time (u, 0) z subluminal boundary space time (u,0)z luminal boundary space time (u, 0) z superluminal boundary space time (u, 0) z temporal boun...

  16. [24]

    Tapar and N

    J. Tapar and N. K. Kishen, S. andEmani, Dynamically tunable asymmetric transmission in pt-symmetric phase gradient metasurface, ACS Photonics 8, 3315 (2021)

  17. [25]

    F. Y., H. Liang, J. Li, D. P. Tsai, and S. Zhang, Emerging trend in unconventional metasur- faces: From nonlinear, non-hermitian to nonclassical metasurfaces, ACS Photonics 9, 2872 (2022)

  18. [26]

    Zhang, X

    L. Zhang, X. Q. Chen, S. Liu, Q. Zhang, J. Zhao, J. Y. Dai, G. D. Bai, X. Wan, Q. Cheng, G. Castaldi, V. Galdi, and T. J. Cui, Space-time-coding digital metasurfaces, Nature Comm. 9, 4334 (2018)

  19. [27]

    A. Li, Y. Li, J. Long, E. Forati, Z. Du, and D. Sievenpiper, Time-modulated nonreciprocal metasurface absorber for surface waves, Optics Letters 45, 1212 (2020)

  20. [28]

    X. Wang, A. D ´ ıaz-Rubio, H. Li, S. A. Tretyakov, and A. Al´ u, Theory and design of multifunc- tional space-time metasurfaces, Phys. Rev. Appl. 13, 044040 (2020)

  21. [29]

    D. Oue, K. Ding, and J. B. Pendry, Noncontact frictional force between surfaces by peristaltic permittivity modulation, Physical Review A 107, 063501 (2023)

  22. [30]

    A. C. Harwood, S. Vezzoli, T. V. Raziman, C. Hooper, R. Tirole, F. Wu, S. Maier, J. B. Pendry, S. A. R. Horsley, and R. Sapienza, Super-luminal synthetic motion with a space-time optical metasurface, arXiv:2407.10809 (2024)

  23. [31]

    Caloz and Z.-L

    C. Caloz and Z.-L. Deck-L´ eger, Spacetime metamaterials, part i: General concepts, IEEE Transactions on Antennas and Propagation 68, 1569 (2020)

  24. [32]

    Caloz and Z.-L

    C. Caloz and Z.-L. Deck-L´ eger, Spacetime metamaterials, part ii: Theory and applications, IEEE Transactions on Antennas and Propagation 68, 1583 (2019)

  25. [33]

    Z. Li, X. Ma, A. Bahrami, Z.-L. Deck-L´ e’ger, and C. Caloz, Space-time fresnel prism, Phys. Rev. Applied 20, 054029 (2023)

  26. [34]

    G. W. Milton and O. Mattei, Field patterns: a new mathematical object, Proc. Roy. Soc. A 473, 20160816 (2017). 26

  27. [35]

    Mostafa, M

    M. Mostafa, M. Mirmoosa, M. Sidorenko, V. Asadchy, and S. Tretyakov, Temporal interfaces in complex electromagnetic materials: an overview, Optical Materials Express14, 1103 (2024)

  28. [36]

    H. Li, S. Yin, and A. Al` u, Nonreciprocity and faraday rotation at time interfaces, Physical Review Letters 128, 173901 (2022)

  29. [37]

    Caloz, Z.-L

    C. Caloz, Z.-L. Deck-L´ eger, A. Bahrami, O. C. Vicente, and Z. Li, Generalized space-time engineered modulation (gstem) metamaterials, arXiv preprint arXiv:2207.06539 (2022)

  30. [38]

    J. D. Jackson, Classical Electrodynamics (John Wiley and Sons, 1962)

  31. [39]

    S. I. Pekar, Dispersion of light in the exciton absorption region of crystals, Zh. Eksp. Teor. Fiz. 33, 1022 (1957)

  32. [40]

    Gratus, R

    J. Gratus, R. Seviour, P. Kinsler, and D. A. Jaroszynski, Temporal boundaries in electromag- netic materials, New Journal of Physics 23, 083032 (2021)

  33. [41]

    G. I. S. and I. M. Ryzhik, Table of Integrals, Series, and Products (Academic Press, 2015)

  34. [42]

    L. D. Landau and E. M. Lifshitz, The Classical Theory of Fields (Butterworth-Heinemann, 2004)

  35. [43]

    Bahrami, K

    A. Bahrami, K. De Kinder, Z. Li, and C. Caloz, Space-time wedges, arxiv:410.23291v1 (2024)

  36. [44]

    Khrabustovskyi, K

    A. Khrabustovskyi, K. Mnasri, M. Plum, C. Stohrer, and C. Rockstuhl, Interface conditions for a metamaterial with strong spatial dispersion, arXiv preprint arXiv:1710.03676 (2017)

  37. [45]

    Z. Li, X. Ma, A. Bahrami, Z.-L. Deck-L´ eger, and C. Caloz, Space-time fresnel prism, Phys. Rev. Appl. 20, 054029 (2023)

  38. [46]

    Dobrzynski and A

    L. Dobrzynski and A. A. Maradudin, Electrostatic edge modes in a dielectric wedge, Physical Review B 6, 3810 (1972)

  39. [47]

    Pendry, P

    J. Pendry, P. A. Huidobro, Y. Luo, and E. Galiffi, Compacted dimensions and singular plas- monic surfaces, Science 358, 915 (2017)

  40. [48]

    Sommerfeld, Mathematical theory of diffraction, in Mathematical Theory of Diffraction (Springer, 2004) pp

    A. Sommerfeld, Mathematical theory of diffraction, in Mathematical Theory of Diffraction (Springer, 2004) pp. 9–68

  41. [49]

    Malyuzhinets, Radiation of sound from the vibrating faces of an arbitrary wedge [part ii], Sov

    D. Malyuzhinets, Radiation of sound from the vibrating faces of an arbitrary wedge [part ii], Sov. Phys. Acoust 1, 240 (1955)

  42. [50]

    Osipov and A

    A. Osipov and A. Norris, The malyuzhinets theory for scattering from wedge boundaries: a review, Wave Motion 29, 313 (1999)

  43. [51]

    Nethercote, R

    M. Nethercote, R. Assier, and I. Abrahams, Analytical methods for perfect wedge diffraction: A review, Wave Motion 93, 102479 (2020). 27

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.