Demosthenes Kazanas
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Demosthenes Kazanas has a total of 105 co-authors. Here are the top co-authors by number of shared publications:
- Dimitris M. Christodoulou
Lowell Center for Space Science and Technology, University of Massachusetts Lowell, Lowell, MA 01854, USA
67 shared publications - Silas G. T. Laycock
Lowell Center for Space Science and Technology, University of Massachusetts Lowell, Lowell, MA 01854, USA
33 shared publications - Ioannis Contopoulos
Research Center for Astronomy and Applied Mathematics, Academy of Athens
18 shared publications - Constantinos Kalapotharakos
NASA Goddard Space Flight Center
17 shared publications - Alice Kust Harding
Los Alamos National Laboratory
15 shared publications - Joseph Sultana
Department of Mathematics, Faculty of Science, University of Malta, MSD2080 Msida, Malta
12 shared publications
Latest Publications
- Open Access
Black Hole Thermodynamics from Macroscopic Vacuum Elasticity
For the past fifty years, the physical foundations of black hole (BH) thermodynamics have remained widely contested because their original derivations rest at the theoretical intersection of general relativity and quantum field theory (QFT). This work provides an alternative macroscopic formulation by treating the physical vacuum in and around a BH as an elastic continuum strained by the presence of mass. Utilizing Hooke’s law of elasticity, we find that the radial strain at the event horizon of every Schwarzschild BH saturates at the same constant value. Under this principle of universal maximum strain, the laws of BH thermodynamics can be formulated within macroscopic continuum mechanics. This dispenses with the conventional QFT derivation in curved spacetime, paralleling the recent macroscopic descriptions of the Casimir effect. Our calculations are carried out using the Reformulated Planck System (RPS), which relies exclusively on Planck’s constant h. This h-native approach prevents the dimensional contamination of 3D continuum mechanics caused by the 2D geometric factor inherently embedded in Dirac’s reduced constant ℏ, a pivotal misstep first recognized in the iconic definitions of the fine-structure constant and the gravitational coupling constant , which long precluded the identification of the -dependence of the weak coupling constant . In BH thermodynamics, this RPS-based approach yields higher Hawking temperatures and lower Bekenstein entropies, both by a factor of .Open AccessBlack Hole Thermodynamics from Macroscopic Vacuum Elasticity
For the past fifty years, the physical foundations of black hole (BH) thermodynamics have remained widely contested because their original derivations rest at the theoretical intersection of general relativity and quantum field theory (QFT). This work provides an alternative macroscopic formulation by treating the physical vacuum in and around a BH as an elastic continuum strained by the presence of mass. Utilizing Hooke’s law of elasticity, we find that the radial strain at the event horizon of every Schwarzschild BH saturates at the same constant value. Under this principle of universal maximum strain, the laws of BH thermodynamics can be formulated within macroscopic continuum mechanics. This dispenses with the conventional QFT derivation in curved spacetime, paralleling the recent macroscopic descriptions of the Casimir effect. Our calculations are carried out using the Reformulated Planck System (RPS), which relies exclusively on Planck’s constant h. This h-native approach prevents the dimensional contamination of 3D continuum mechanics caused by the 2D geometric factor inherently embedded in Dirac’s reduced constant ℏ, a pivotal misstep first recognized in the iconic definitions of the fine-structure constant and the gravitational coupling constant , which long precluded the identification of the -dependence of the weak coupling constant . In BH thermodynamics, this RPS-based approach yields higher Hawking temperatures and lower Bekenstein entropies, both by a factor of . - Open Access
Plausible Sources of Dark Energy and Associated Vacuum Properties: Implications for Newton’s G, MOND’s a0, Vacuum Invariants, and the Tully–Fisher and Faber–Jackson Galactic Relations
We believe that the origin of the universal dark energy may crucially depend on the behavior of the gravitational constant G. If G is constant throughout the universe, then the dark energy density is supported by the vacuum via its constant and evolving properties. On the other hand, in varying-G gravity (whose low-acceleration limit is MOND), is a manifestation of radial G-gradients in the source of gravity. We estimate the present-day dark energy density of the universe in these two independent cases without using conventional Planck-2018 modeling in deriving the expressions for . The constant-G derivation uses dimensional analysis, vacuum constants, and a newly discovered evolving bridge between vacuum mechanical and electromagnetic quantities. The varying-G derivation relies on the MOND critical acceleration , the source of gravity that falls off as ∼ at large distances r, and the assumption that the present-day energy density can be estimated by spatially averaging this radial profile over the MOND volume , where and c is the speed of light in vacuum. The agreement between these two determinations and the Planck-2018 results from CDM modeling is at the percent level, so that the results cannot distinguish clearly between constant-G and varying-G gravity. The analysis further indicates that the Newtonian constant , the MOND constant , and the Planck units of force, power, voltage, and current can be regarded as empirical vacuum constants within the proposed framework, alongside the well-known resistive properties of the vacuum, whereas charge, capacitance, inductance, and various fields are scale-dependent properties evolving in the expanding universe since the Stoney era. Ultimately, the vacuum behaves as a remarkably stiff elastic medium under stress, irrespective of the presence or absence of matter. This property has long been encoded, albeit inconspicuously, in the much discussed Tully–Fisher and Faber–Jackson relations, as well as in the Casimir effect and the field equations of General Relativity.Open AccessPlausible Sources of Dark Energy and Associated Vacuum Properties: Implications for Newton’s G, MOND’s a0, Vacuum Invariants, and the Tully–Fisher and Faber–Jackson Galactic Relations
We believe that the origin of the universal dark energy may crucially depend on the behavior of the gravitational constant G. If G is constant throughout the universe, then the dark energy density is supported by the vacuum via its constant and evolving properties. On the other hand, in varying-G gravity (whose low-acceleration limit is MOND), is a manifestation of radial G-gradients in the source of gravity. We estimate the present-day dark energy density of the universe in these two independent cases without using conventional Planck-2018 modeling in deriving the expressions for . The constant-G derivation uses dimensional analysis, vacuum constants, and a newly discovered evolving bridge between vacuum mechanical and electromagnetic quantities. The varying-G derivation relies on the MOND critical acceleration , the source of gravity that falls off as ∼ at large distances r, and the assumption that the present-day energy density can be estimated by spatially averaging this radial profile over the MOND volume , where and c is the speed of light in vacuum. The agreement between these two determinations and the Planck-2018 results from CDM modeling is at the percent level, so that the results cannot distinguish clearly between constant-G and varying-G gravity. The analysis further indicates that the Newtonian constant , the MOND constant , and the Planck units of force, power, voltage, and current can be regarded as empirical vacuum constants within the proposed framework, alongside the well-known resistive properties of the vacuum, whereas charge, capacitance, inductance, and various fields are scale-dependent properties evolving in the expanding universe since the Stoney era. Ultimately, the vacuum behaves as a remarkably stiff elastic medium under stress, irrespective of the presence or absence of matter. This property has long been encoded, albeit inconspicuously, in the much discussed Tully–Fisher and Faber–Jackson relations, as well as in the Casimir effect and the field equations of General Relativity. - Open Access
- 23 September 2026
- Published by MDPI AG in Preprints.org
Black Hole Thermodynamics from Macroscopic Vacuum Elasticity
For the past fifty years, the physical foundations of black hole (BH) thermodynamics have remained heavily contested because their original derivations rest at the theoretical intersection of general relativity and quantum field theory (QFT). This work provides an alternative macroscopic formulation by treating the physical vacuum in and around a BH as an elastic continuum curved by the presence of mass. According to Hooke's law of elasticity, the radial strain at the event horizons of all BHs must saturate at the exact same constant value. Under this principle of universal maximum strain, the laws of BH thermodynamics emerge directly from macroscopic continuum mechanics. This eliminates the need for QFT input, mirroring the contemporary macroscopic descriptions of the Casimir effect. Our calculations are formalized using the Reformulated Planck System (RPS), which relies exclusively on Planck's constant $h$. This native approach prevents the dimensional contamination of 3D continuum mechanics caused by the 2D geometric factor inherently embedded in Dirac's reduced constant $\hbar$, a salient miscue first recognized in the iconic definitions of the fine-structure constant α and the gravitational coupling constant αg which firmly precluded the identification of the α-dependence of the weak coupling constant \( αw = \sqrt{\alpha} \). In BH thermodynamics, this RPS-based approach reveals higher Hawking temperatures and lower Bekenstein entropies, both by a factor of \( 2\pi \).- 23 September 2026
- Published by MDPI AG in Preprints.org
Open AccessBlack Hole Thermodynamics from Macroscopic Vacuum Elasticity
For the past fifty years, the physical foundations of black hole (BH) thermodynamics have remained heavily contested because their original derivations rest at the theoretical intersection of general relativity and quantum field theory (QFT). This work provides an alternative macroscopic formulation by treating the physical vacuum in and around a BH as an elastic continuum curved by the presence of mass. According to Hooke's law of elasticity, the radial strain at the event horizons of all BHs must saturate at the exact same constant value. Under this principle of universal maximum strain, the laws of BH thermodynamics emerge directly from macroscopic continuum mechanics. This eliminates the need for QFT input, mirroring the contemporary macroscopic descriptions of the Casimir effect. Our calculations are formalized using the Reformulated Planck System (RPS), which relies exclusively on Planck's constant $h$. This native approach prevents the dimensional contamination of 3D continuum mechanics caused by the 2D geometric factor inherently embedded in Dirac's reduced constant $\hbar$, a salient miscue first recognized in the iconic definitions of the fine-structure constant α and the gravitational coupling constant αg which firmly precluded the identification of the α-dependence of the weak coupling constant \( αw = \sqrt{\alpha} \). In BH thermodynamics, this RPS-based approach reveals higher Hawking temperatures and lower Bekenstein entropies, both by a factor of \( 2\pi \). - Open Access
- 23 September 2026
- Published by MDPI AG in Preprints.org
Plausible Sources of Dark Energy and Associated Vacuum Properties: Implications for Newton’s G, MOND’s a0, Vacuum Invariants, and the Tully–Fisher and Faber–Jackson Galactic Relations
We believe that the origin of the universal dark energy may crucially depend on the behavior of the gravitational constant $G$. If $G$ is constant throughout the universe, then the dark energy density u0 is supported by the vacuum via its constant and evolving properties. On the other hand, in varying-$G$ gravity (whose low-acceleration limit is MOND), u0 is a manifestation of radial $G$-gradients in the source of gravity. We estimate the present-day dark energy density of the universe in these two independent cases without using conventional Planck-2018 modeling in deriving the expressions for u0. The constant-$G$ derivation uses dimensional analysis, vacuum constants, and a newly discovered evolving bridge between vacuum mechanical and electromagnetic quantities. The varying-$G$ derivation relies on the MOND critical acceleration $a_0^{}$, the source of gravity that falls off as $\sim r^{-2}$ at large distances $r$, and the assumption that the present-day energy density $u_0^{}$ can be estimated by spatially averaging this radial profile over the MOND volume $\frac{4\pi}{3}r_0^{~3}$, where $r_0^{}=c^2/a_0^{}$ and $c$ is the speed of light in vacuum. The agreement between these two determinations and the Planck-2018 results from $\Lambda$CDM modeling is at the percent level, so that the results cannot distinguish clearly between constant-$G$ and varying-$G$ gravity. The analysis further indicates that the Newtonian constant G0, the MOND constant $a_0^{}$, and the Planck units of force, power, voltage, and current should be accepted as empirical vacuum invariants of the same stature as the well-known resistive properties of the vacuum; whereas charge, capacitance, inductance, and various fields are scale-dependent properties evolving in the expanding universe since the Stoney era. Ultimately, the vacuum behaves as a remarkably stiff elastic medium under stress, irrespective of the presence or absence of matter. This property has long been encoded, albeit inconspicuously, in the much discussed Tully–Fisher and Faber–Jackson relations, as well as in the Casimir effect and the field equations of General Relativity.- 23 September 2026
- Published by MDPI AG in Preprints.org
Open AccessPlausible Sources of Dark Energy and Associated Vacuum Properties: Implications for Newton’s G, MOND’s a0, Vacuum Invariants, and the Tully–Fisher and Faber–Jackson Galactic Relations
We believe that the origin of the universal dark energy may crucially depend on the behavior of the gravitational constant $G$. If $G$ is constant throughout the universe, then the dark energy density u0 is supported by the vacuum via its constant and evolving properties. On the other hand, in varying-$G$ gravity (whose low-acceleration limit is MOND), u0 is a manifestation of radial $G$-gradients in the source of gravity. We estimate the present-day dark energy density of the universe in these two independent cases without using conventional Planck-2018 modeling in deriving the expressions for u0. The constant-$G$ derivation uses dimensional analysis, vacuum constants, and a newly discovered evolving bridge between vacuum mechanical and electromagnetic quantities. The varying-$G$ derivation relies on the MOND critical acceleration $a_0^{}$, the source of gravity that falls off as $\sim r^{-2}$ at large distances $r$, and the assumption that the present-day energy density $u_0^{}$ can be estimated by spatially averaging this radial profile over the MOND volume $\frac{4\pi}{3}r_0^{~3}$, where $r_0^{}=c^2/a_0^{}$ and $c$ is the speed of light in vacuum. The agreement between these two determinations and the Planck-2018 results from $\Lambda$CDM modeling is at the percent level, so that the results cannot distinguish clearly between constant-$G$ and varying-$G$ gravity. The analysis further indicates that the Newtonian constant G0, the MOND constant $a_0^{}$, and the Planck units of force, power, voltage, and current should be accepted as empirical vacuum invariants of the same stature as the well-known resistive properties of the vacuum; whereas charge, capacitance, inductance, and various fields are scale-dependent properties evolving in the expanding universe since the Stoney era. Ultimately, the vacuum behaves as a remarkably stiff elastic medium under stress, irrespective of the presence or absence of matter. This property has long been encoded, albeit inconspicuously, in the much discussed Tully–Fisher and Faber–Jackson relations, as well as in the Casimir effect and the field equations of General Relativity. - Open Access
- 4 September 2026
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 1008 (2) , 215
The Swept-back Multipolar Magnetic Field of Neutron Stars: Application to NICER MSP J0030+0451
NICER observations of millisecond pulsars (MSPs) suggest that non-dipolar magnetic fields are required in order to explain their surface X-ray hotspots. C. Kalapotharakos et al. modeled the NICER light curve of MSP J0030+0451 (J0030) using a static-vacuum offset dipole-plus-quadrupole field and corresponding force-free (FF) solutions to jointly reproduce the X-ray and Fermi-LAT γ -ray emission. We substitute their static-vacuum field model with a more realistic swept-back configuration that accounts for rotational effects. This field more closely resembles the corresponding FF solutions, making it a more physically motivated choice for future multiwavelength modeling. We adopt a centered swept-back vacuum multipolar magnetic field (SVM2F; J. Pétri), expressed as a complete expansion in vector spherical harmonics, enabling flexible descriptions of arbitrary magnetic field geometries. We introduce a metric to quantify the complexity among different field prescriptions, illustrated for the static offset vacuum field. To efficiently explore parameter space, we train a neural network surrogate (G. Olmschenk et al.) on SVM2F light curves, including components up to the octupole, accelerating Markov chain Monte Carlo sampling by ∼10 3 compared to direct physical model evaluations. Applying this framework to J0030, we constrain the field parameter space and find that a centered swept-back multipolar field including terms up to the octupole adequately reproduces the bolometric thermal X-ray light curve. Our study highlights the importance and inherent complexity of prescribing different multipolar magnetic field models for rotating stars, and can be extended to other MSPs to ultimately constrain the masses and radii of neutron stars, and hence their equation of state.
- 4 September 2026
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 1008 (2) , 215
Open AccessThe Swept-back Multipolar Magnetic Field of Neutron Stars: Application to NICER MSP J0030+0451
NICER observations of millisecond pulsars (MSPs) suggest that non-dipolar magnetic fields are required in order to explain their surface X-ray hotspots. C. Kalapotharakos et al. modeled the NICER light curve of MSP J0030+0451 (J0030) using a static-vacuum offset dipole-plus-quadrupole field and corresponding force-free (FF) solutions to jointly reproduce the X-ray and Fermi-LAT γ -ray emission. We substitute their static-vacuum field model with a more realistic swept-back configuration that accounts for rotational effects. This field more closely resembles the corresponding FF solutions, making it a more physically motivated choice for future multiwavelength modeling. We adopt a centered swept-back vacuum multipolar magnetic field (SVM2F; J. Pétri), expressed as a complete expansion in vector spherical harmonics, enabling flexible descriptions of arbitrary magnetic field geometries. We introduce a metric to quantify the complexity among different field prescriptions, illustrated for the static offset vacuum field. To efficiently explore parameter space, we train a neural network surrogate (G. Olmschenk et al.) on SVM2F light curves, including components up to the octupole, accelerating Markov chain Monte Carlo sampling by ∼10 3 compared to direct physical model evaluations. Applying this framework to J0030, we constrain the field parameter space and find that a centered swept-back multipolar field including terms up to the octupole adequately reproduces the bolometric thermal X-ray light curve. Our study highlights the importance and inherent complexity of prescribing different multipolar magnetic field models for rotating stars, and can be extended to other MSPs to ultimately constrain the masses and radii of neutron stars, and hence their equation of state.
- Open Access
Composite Universal Constants Combining 2–5 Known Constants Reveal Latent Connections Between Disparate Physical Regimes and the Role of Dimensionless Constants in Systems of Units
We introduce a new method of dimensional analysis based on complete systems of units, such as the metric and Planck systems, in which fundamental dimensionless constants arise naturally. In fact, it is the reformulated Planck system that communicates its dimensionless constants to the metric or any other system. The method reveals additional complex dynamical scales and physical effects beyond those amenable to conventional dimensional analysis. We formulate our strategy in simple settings involving pairs of seemingly unrelated constants, and then we extend the analysis to more complicated cases involving combinations of three to five well-known universal constants. In constructions involving several unrelated constants, the method captures increasingly complex effects and places two or more disparate physics areas into a single framework connecting them by never-before-seen combinations of fundamental dimensionless constants, such as the fine-structure constant and the gravitational coupling constant. Thus, this method provides a pathway to blending descriptions of two or more fundamental interactions that have so far eluded a consistent theoretical formulation.
Open AccessComposite Universal Constants Combining 2–5 Known Constants Reveal Latent Connections Between Disparate Physical Regimes and the Role of Dimensionless Constants in Systems of Units
We introduce a new method of dimensional analysis based on complete systems of units, such as the metric and Planck systems, in which fundamental dimensionless constants arise naturally. In fact, it is the reformulated Planck system that communicates its dimensionless constants to the metric or any other system. The method reveals additional complex dynamical scales and physical effects beyond those amenable to conventional dimensional analysis. We formulate our strategy in simple settings involving pairs of seemingly unrelated constants, and then we extend the analysis to more complicated cases involving combinations of three to five well-known universal constants. In constructions involving several unrelated constants, the method captures increasingly complex effects and places two or more disparate physics areas into a single framework connecting them by never-before-seen combinations of fundamental dimensionless constants, such as the fine-structure constant and the gravitational coupling constant. Thus, this method provides a pathway to blending descriptions of two or more fundamental interactions that have so far eluded a consistent theoretical formulation.
- Open Access
- 8 May 2026
- Published by MDPI AG in Preprints.org
Composite Universal Constants Combining 2–5 Known Constants Reveal Latent Connections Between Disparate Physical Regimes and the Role of Dimensionless Constants in Systems of Units
We introduce a new method of dimensional analysis based on complete systems of units, such as the metric and Planck systems, in which fundamental dimensionless constants arise naturally. In fact, it is the reformulated Planck system that communicates its dimensionless constants to the metric or any other system. The method reveals additional complex dynamical scales and physical effects beyond those amenable to conventional dimensional analysis. We formulate our strategy in simple settings involving pairs of seemingly unrelated constants, and then we extend the analysis to more complicated cases involving combinations of three to five well-known universal constants. In constructions involving several unrelated constants, the method captures increasingly complex effects and places two or more disparate physics areas into a single framework connecting them by never-before-seen combinations of fundamental dimensionless constants, such as the fine-structure constant and the gravitational coupling constant. Thus, this method provides an alternative pathway to unified descriptions of fundamental interactions that have so far eluded a consistent theoretical formulation.
- 8 May 2026
- Published by MDPI AG in Preprints.org
Open AccessComposite Universal Constants Combining 2–5 Known Constants Reveal Latent Connections Between Disparate Physical Regimes and the Role of Dimensionless Constants in Systems of Units
We introduce a new method of dimensional analysis based on complete systems of units, such as the metric and Planck systems, in which fundamental dimensionless constants arise naturally. In fact, it is the reformulated Planck system that communicates its dimensionless constants to the metric or any other system. The method reveals additional complex dynamical scales and physical effects beyond those amenable to conventional dimensional analysis. We formulate our strategy in simple settings involving pairs of seemingly unrelated constants, and then we extend the analysis to more complicated cases involving combinations of three to five well-known universal constants. In constructions involving several unrelated constants, the method captures increasingly complex effects and places two or more disparate physics areas into a single framework connecting them by never-before-seen combinations of fundamental dimensionless constants, such as the fine-structure constant and the gravitational coupling constant. Thus, this method provides an alternative pathway to unified descriptions of fundamental interactions that have so far eluded a consistent theoretical formulation.
- Open Access
A Common Origin of the H0 and S8 Cosmological Tensions and a Resolution Within a Modified ΛCDM Framework
The two most severe cosmological tensions in the Hubble constant and the matter clustering amplitude have the same relative discrepancy of 8.3%, which suggests that they may have a common origin. Modifications of gravity and exotic dark fields with numerous free parameters introduced in the Einstein field equations often struggle to simultaneously alleviate both tensions; thus, we need to look for a common cause within the standard CDM framework. At the same time, linear perturbation analyses of matter in the expanding CDM universe have always neglected the impact of comoving peculiar velocities (generally thought to be a second-order effect), the same velocities that, in physical space, cannot be fully accounted for in the observed late-time universe when the cosmic distance ladder is used to determine the local value of . We have reworked the linear density perturbation equations in the conformal Newtonian gauge (sub-horizon limit) by introducing an additional drag force per unit mass in the Euler equation with , where is a positive dimensionless constant and is the time-dependent Hubble friction. We find that a damping parameter of is sufficient to resolve the tension by suppressing the growth of structure at low redshifts, starting at to achieve , respectively. Furthermore, we argue that the physical source causing this additional friction (a tidal field generated by nonlinear structures in the late-time universe) is also responsible for a systematic error in the local determinations of —the inability to subtract peculiar tidal velocities along the lines of sight when determining the Hubble flow via the cosmic distance ladder. Finally, the dual action of the tidal field on the expanding background—reducing both the matter and the dark energy sources of the squared Hubble rate , thereby holding back the cosmic acceleration —is of fundamental importance in resolving cosmological tensions and can also substantially alleviate the density coincidence problem.Open AccessA Common Origin of the H0 and S8 Cosmological Tensions and a Resolution Within a Modified ΛCDM Framework
The two most severe cosmological tensions in the Hubble constant and the matter clustering amplitude have the same relative discrepancy of 8.3%, which suggests that they may have a common origin. Modifications of gravity and exotic dark fields with numerous free parameters introduced in the Einstein field equations often struggle to simultaneously alleviate both tensions; thus, we need to look for a common cause within the standard CDM framework. At the same time, linear perturbation analyses of matter in the expanding CDM universe have always neglected the impact of comoving peculiar velocities (generally thought to be a second-order effect), the same velocities that, in physical space, cannot be fully accounted for in the observed late-time universe when the cosmic distance ladder is used to determine the local value of . We have reworked the linear density perturbation equations in the conformal Newtonian gauge (sub-horizon limit) by introducing an additional drag force per unit mass in the Euler equation with , where is a positive dimensionless constant and is the time-dependent Hubble friction. We find that a damping parameter of is sufficient to resolve the tension by suppressing the growth of structure at low redshifts, starting at to achieve , respectively. Furthermore, we argue that the physical source causing this additional friction (a tidal field generated by nonlinear structures in the late-time universe) is also responsible for a systematic error in the local determinations of —the inability to subtract peculiar tidal velocities along the lines of sight when determining the Hubble flow via the cosmic distance ladder. Finally, the dual action of the tidal field on the expanding background—reducing both the matter and the dark energy sources of the squared Hubble rate , thereby holding back the cosmic acceleration —is of fundamental importance in resolving cosmological tensions and can also substantially alleviate the density coincidence problem. - Open Access
- 20 February 2026
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 999 (1) , 5
A Comprehensive Interpretation of Fermi-LAT Pulsars: Fundamental-plane Death Border, Visibility Thresholds, and GeV–TeV Unification
We present a framework that links equatorial-current-sheet (ECS) physics to catalog-level, phase-averaged gamma-ray pulsar properties. Guided by analytic scalings and particle-in-cell (PIC) simulations, we show that the pulsar “Fundamental Plane” (relating gamma-ray luminosity, spectral cutoff energy, spin-down power E ̇ , and surface magnetic field) is bounded by two regimes: a radiation-reaction-limited branch and a potential-drop-limited branch. Their intersection defines a transition in E ̇ that maps to a gamma-ray visibility threshold on the P – P ̇ diagram, above which detectability is set by distance and beaming, and below which both cutoff energy and efficiency decline rapidly. Placing ATNF pulsars and McGill magnetars onto these planes reproduces the observed Fermi occupancy, with millisecond pulsars (MSPs) on the observable side, young pulsars (YPs) straddling the threshold, and magnetars clustering at or just below it. At higher E ̇ , both MSPs and YPs depart from the maximal radiation-reaction-limited envelope at similar cutoff energies, suggesting that enhanced pair creation screens the accelerating electric field in the ECS. We interpret this behavior with a compactness-based criterion for optically thin γγ pair feedback in or near the ECS and briefly note an extension to γγ → μ ± that could yield pulsed multi-TeV neutrinos in the most energetic systems. The framework predicts a MeV-bright, GeV-faint corridor below Fermi sensitivity, a target for next-generation MeV missions. Finally, motivated by the recent HESSII detection of pulsed multi-TeV emission from Vela, we use PIC particle distributions with a seed-photon model to reproduce a multi-TeV inverse-Compton component alongside the GeV curvature emission, supporting a unified ECS-based GeV–TeV origin.
- 20 February 2026
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 999 (1) , 5
Open AccessA Comprehensive Interpretation of Fermi-LAT Pulsars: Fundamental-plane Death Border, Visibility Thresholds, and GeV–TeV Unification
We present a framework that links equatorial-current-sheet (ECS) physics to catalog-level, phase-averaged gamma-ray pulsar properties. Guided by analytic scalings and particle-in-cell (PIC) simulations, we show that the pulsar “Fundamental Plane” (relating gamma-ray luminosity, spectral cutoff energy, spin-down power E ̇ , and surface magnetic field) is bounded by two regimes: a radiation-reaction-limited branch and a potential-drop-limited branch. Their intersection defines a transition in E ̇ that maps to a gamma-ray visibility threshold on the P – P ̇ diagram, above which detectability is set by distance and beaming, and below which both cutoff energy and efficiency decline rapidly. Placing ATNF pulsars and McGill magnetars onto these planes reproduces the observed Fermi occupancy, with millisecond pulsars (MSPs) on the observable side, young pulsars (YPs) straddling the threshold, and magnetars clustering at or just below it. At higher E ̇ , both MSPs and YPs depart from the maximal radiation-reaction-limited envelope at similar cutoff energies, suggesting that enhanced pair creation screens the accelerating electric field in the ECS. We interpret this behavior with a compactness-based criterion for optically thin γγ pair feedback in or near the ECS and briefly note an extension to γγ → μ ± that could yield pulsed multi-TeV neutrinos in the most energetic systems. The framework predicts a MeV-bright, GeV-faint corridor below Fermi sensitivity, a target for next-generation MeV missions. Finally, motivated by the recent HESSII detection of pulsed multi-TeV emission from Vela, we use PIC particle distributions with a seed-photon model to reproduce a multi-TeV inverse-Compton component alongside the GeV curvature emission, supporting a unified ECS-based GeV–TeV origin.