PaperPanorama

HEP Phenomenology·hep-ph

Fri·Aug 7, 2026

25 papers17 primary·8 cross-listed

  1. 01

    Baryogenesis via the CKM Matrix with Minimal Flavor Violation

    Innes Bigaran🇺🇸 · Gordan Krnjaic🇺🇸 · Kevin Langhoff🇺🇸 · Huangyu Xiao🇺🇸

    It is often claimed Standard Model CP violation is insufficient for baryogenesis. We present a counterexample using minimal flavor violation (MFV) in which all CP-violating effects arise from the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Our scenario involves a leptoquark field with MFV-preserving interactions whose decays to Standard Model particles yield the observed baryon asymmetry in the early universe. Unlike previous efforts to realize baryogenesis through the CP violation of the CKM matrix, our scenario does not require any time-variation of model parameters.

    hep-phastro-ph.CO0 citations
  2. 02

    Axion-driven spontaneous leptogenesis, precisely

    Konstantin Kuckenberg🇩🇪 · Martin A. Mojahed🇮🇹 · Kai Schmitz🇩🇪 · Hidenaga Watanabe🇯🇵

    We revisit a minimal scenario for spontaneous leptogenesis where the asymmetry generation is driven by a heavy axion-like field evolving via standard misalignment. We focus on the simplest framework in which lepton number violation originates from the dimension-five Weinberg operator and contributions from standard thermal leptogenesis become negligible. The asymmetry is computed by solving a set of transport equations, which incorporate fully flavor-dependent interaction rates for the Weinberg operator that are presented here for the first time. We also derive a simple algebraic master formula for the generated asymmetry, valid for arbitrary axion velocities and classically shift-symmetric couplings to the Standard Model, that reproduces the -production dynamics of the full set of transport equations in controlled parameter regions. Along the way, we quantify the importance of low-scale neutrino masses and the two mass orderings on the final prediction for the generated asymmetry. Finally, we assess the cosmological viability of different axion couplings by accounting for entropy dilution from late-time axion decays and imposing constraints from baryonic isocurvature perturbations. We demonstrate that explaining the baryon asymmetry via standard Majoron misalignment is under severe tension due to dilution from late-time decays. In contrast, axions coupled to strong or weak sphalerons can successfully produce the observed asymmetry for decay constants near the energy scale of grand unification and axion oscillation temperatures GeV, provided a cosmological history featuring high-scale inflation and efficient reheating.

    hep-phastro-ph.CO3 citations
  3. 03

    First-principles upper bounds on dark matter-electron scattering rates from condensed matter sum rules

    Bradford A. Barker🇺🇸 · Jay Epstein🇨🇦 · Luke James🇨🇦 · Yonatan Kahn🇨🇦 · Elizabeth A. Peterson🇺🇸 · Anirudh Prabhu🇺🇸 · Tanner Trickle🇺🇸 · Samuel L. Watkins🇺🇸

    A wide variety of condensed matter systems are used or proposed as detectors to search for dark matter-electron scattering. In general, the scattering rate depends on detailed knowledge of the electronic properties of these systems. However, when dark matter couples to electron density, the dark matter-electron scattering rate can be related to the electron energy loss function, whose integrals are bounded by first-principles sum rules that rely on only a few macroscopic target properties. In this paper, we use these first-principles sum rules to derive upper bounds on the dark matter-electron scattering rate depending on only a few material properties: the plasma frequency , the target mass density , and the static (longitudinal) dielectric function at finite momentum transfer, . The bulk material properties and vary only over a limited range across a wide variety of materials, and to a good approximation, the generic large- dependence of can be understood from a simple scaling law depending only on which we verify with analytic and numerical examples. Thus, our upper bounds are largely material-agnostic, and place a fundamental limit on the sensitivity of any dark matter-electron direct detection experiment probing the coupling to electron density.

    hep-phcond-mat.mtrl-scihep-ex0 citations
  4. 04

    Novel Signatures of Matter-Induced Dark Matter Decay in Large-Volume Neutrino Telescopes

    Hooman Davoudiasl🇺🇸 · Dan Hooper🇺🇸 · Samyak Jain🇺🇸

    Large-volume neutrino telescopes offer a unique opportunity to search for decaying dark matter through events containing a pair of energetic, highly non-collimated muon tracks emerging from a common vertex. Such events would have negligible Standard Model backgrounds and would constitute a striking signature of new physics. Conventional dark matter annihilation or decay, however, is too strongly constrained to produce an observable rate of such events. We therefore consider scenarios in which an excited dark matter state is extremely long-lived in vacuum but decays much more rapidly in the presence of ordinary matter. We present two realizations of this mechanism. In the first, a long-range scalar field sourced by ordinary matter modifies the dark-sector mass spectrum, kinematically opening the decay near the Earth while leaving it forbidden in vacuum. In the second, the scalar background induces kinetic mixing between a heavy and the photon, greatly enhancing the three-body decay in matter-rich environments. We calculate the resulting distributions of muon energies and opening angles and show that viable regions of parameter space can yield observable event rates in IceCube, KM3NeT, and other large-volume neutrino telescopes while remaining consistent with existing constraints. We also briefly consider the sensitivity of IceCube to multi-muon events produced by the decays of cosmologically long-lived charged particles with masses TeV.

    hep-phastro-ph.COastro-ph.HE1 citation
  5. 05

    GOOFy-compatible 3HDMs and beyond

    I. de Medeiros Varzielas🇵🇹 · A. Kunčinas🇪🇸

    Beyond conventional Higgs-family and general CP transformations, one may also consider a broader class of non-standard "GOOFy" transformations, in which the scalar fields and their conjugates are assigned related but inequivalent transformations. Although these transformations are not symmetries of a full Lagrangian in the conventional sense, some nevertheless stabilise the scalar potential. Their impact on the quadratic sector has not yet been systematically classified. We develop a sign-orbit technique to determine the bilinear structures compatible with these transformations. Applied to three-Higgs-doublet models, and formulated so as to extend to larger multi-Higgs sectors, the method shows that a non-vanishing GOOFy-compatible quadratic sector exists only when two independent conditions are met: the underlying group admits a non-trivial sign character, and that character is realised within the tensor product of the scalar representation and its conjugate. As a key consequence, we demonstrate that the renormalisation-group stability of the manifold in isolation is not a generic feature of multi-Higgs potentials, but rather a direct consequence of special algebraic properties of . These results provide a classification of the admissible GOOFy quadratic structures and their invariant bilinear subspaces, highlighting the algebraic obstructions to their renormalisation-group stability.

    hep-phhep-th0 citations
  6. 06

    Beyond Borel Windows: A Systematic Optimization Framework for QCD Sum Rules

    Raphael M. Albuquerque🇧🇷

    We propose a systematic optimization framework for determining the sum rule window in QCD Laplace sum rules. Instead of relying primarily on fixed convergence percentages and visual plateau selection, the procedure combines an OPE entropy criterion, local mass stationarity, and a correlated analysis of the Laplace parameter , the continuum threshold , and the interpolating-current mixing angle . The normalized OPE entropy is introduced to quantify the redistribution of the QCD contributions between the perturbative and nonperturbative sectors and to delimit an initial Working Region. This domain is subsequently refined by minimizing the residual variation of the mass estimator and requiring weak sensitivity to the continuum threshold and to the current composition. As an application, we study the lowest fully charmed tetraquark state with quantum numbers using a mixed diquark--antidiquark and meson--meson interpolating current. The optimization selects , , and , leading to the mass prediction . The predicted state lies in the near-threshold region of the di- spectrum and is compatible, within uncertainties, with the lowest resonant component reported by ATLAS and with the enhancement parametrized as in the recent CMS publication. The proposed framework provides a reproducible way of identifying finite domains of reduced auxiliary-parameter sensitivity and of incorporating the remaining dependence into the final uncertainty.

    hep-phhep-th0 citations
  7. 07

    Photon-nucleon entanglement in Compton scattering at low and high energies

    Yoshitaka Hatta🇺🇸 · Víctor Martínez-Fernández🇫🇷

    We study spin-spin entanglement in the final state photon-nucleon system in Compton scattering, both at low energy below the pion threshold and at high energy in perturbative QCD to next-to-leading order. We first establish a no-go theorem showing that, for any spin- target, entanglement cannot be generated in unpolarized Compton scattering if the scattering amplitudes are real. We then consider polarized Compton scattering off the electron, the proton and the neutron. At low energy, we uncover a rich variety of maximally entangled Bell states and their unitary equivalents realized across different regions of the kinematic plane. Interestingly, the proton and neutron targets exhibit distinct patterns of entanglement. In the neutron case, the electric and magnetic polarizabilities dramatically influence the pattern and even the existence of entanglement. This suggests that entanglement can serve as a novel tool for investigating the detailed electromagnetic properties of the nucleons.

    hep-phhep-exnucl-exnucl-th+12 citations
  8. 08

    HiggsTools for LHC Run 3 and Beyond

    Henning Bahl🇩🇪 · Thomas Biekötter🇪🇸 · Sven Heinemeyer🇪🇸 · Kateryna Radchenko Serdula🇪🇸 · Georg Weiglein🇩🇪

    HiggsTools, including the subpackages HiggsPredictions, HiggsBounds, and HiggsSignals, is a toolbox for Beyond-the-SM (BSM) scalar phenomenology at the LHC. It provides BSM model predictions, tests the model against experimental limits from searches for BSM scalars and derives constraints from the measurements of the properties of the discovered Higgs boson. We present a variety of improvements to the HiggsTools framework, preparing it for the results of LHC Run 3 and the HL-LHC. HiggsPredictions now provides additional cross-section predictions for centre-of-mass energies of 13.6 and 14 TeV. Moreover, it now includes cross-section predictions for resonant and non-resonant Higgs-boson pair production. For HiggsBounds, we describe the recasting of searches using multi-top final states, explain their implementation and highlight the impact of the experimental sensitivity of those results. Furthermore, we discuss the implementation of coupling-dependent limits on non-resonant Higgs boson pair production, as well as the improved handling of searches conducted prior to the Higgs boson discovery. For HiggsSignals we describe several improvements for the case of scalars with mass uncertainties.

    hep-ph3 citations
  9. 09

    Spinor tunnelling amplitudes from all-order Feynman diagram summation

    Max Fleming🇦🇺 · Cedric Simenel🇦🇺

    This work presents a non-perturbative quantum field theoretic computation of spinor tunnelling through a potential barrier. Within position space potential formalism, we identify coupled recursion relations forming a self-consistent integral equation. Our method, enabling both analytical and numerical approaches, transforms into a formalism admitting both numerical framework for arbitrary potentials and analytical exact results for select barriers. For the rectangular barrier, the QFT-derived amplitudes reproduce the relativistic quantum mechanical (RQM) results, thus establishing a foundation for future calculation of beyond-RQM field-theoretic corrections.

    hep-ph0 citations
  10. 10

    Coherent and Stochastic Axion Dark Matter from Thermal Relaxation

    Shahid Hussain Gurmani🇨🇳 · Arzu Cilli🇹🇷 · Phongpichit Channuie🇹🇭 · Ahmadjon Abdujabbarov🇨🇳 · Farruh Atamurotov🇺🇿 · Ertan Güdekli🇹🇷

    An axion driven toward a thermal minimum need not remain a coherent condensate. We derive the coupled attenuation of the field mean and production of stochastic momentum modes in an expanding plasma. A single momentum dependent optical depth partitions every mode between coherent power and Bose occupation, placing standard misalignment, partial relaxation, and stochastic production in one dynamical relation. Finite spatial and temporal response suppresses high momentum production, so the stochastic relic has lower mean momentum and a shorter free streaming length than an equilibrium population at fixed mass and bath temperature. A weakly coupled realization produces the dark matter abundance, reduces inherited coherent isocurvature, and confines production correlations to scales removed by collisionless propagation. Thermal relaxation therefore determines the composition, momentum distribution, and transported structure of axion dark matter.

    hep-phgr-qchep-th0 citations
  11. 11

    Revisiting the decay in light of the BESIII measurement

    Meng-Yuan Li🇨🇳 · Jing Tang🇨🇳 · Wen-Tao Lyu🇨🇳 · Shi-Chen Xue🇨🇳 · En Wang🇨🇳

    Motivated by the latest BESIII measurements on , we perform a systematic theoretical study of this decay. We take into account contributions from the state dynamically generated by -wave pseudoscalar meson-octet baryon interactions, the resonance originating from the -wave pseudoscalar meson-pseudoscalar meson interactions, together with the intermediate states and . Our results indicate that provides a significant contribution to this process. The inclusion of hardly improves the fitting quality, while the nucleon resonances play a crucial role in describing the experimental behavior of the invariant mass spectrum in both low and high energy regions. Restricted by insufficient experimental statistics and a coarse bin size of 33 MeV, the precise contribution fraction of cannot be reliably extracted. We propose future higher-precision and higher-statistics experimental measurements of , which can help reveal the intrinsic nature of and quantify the roles of different excited nucleon states in this decay.

    hep-ph0 citations
  12. 12

    Net electron spin rotation in a plane-wave pulse: Holonomy set by the anomalous magnetic moment

    N. S. Akintsov🇨🇳 · A. P. Nevecheria🇷🇺 · S. N. Andreev🇷🇺 · Qing-Hua Qin🇨🇳

    We compute the spin rotation that survives after a relativistic electron has crossed a plane-wave laser pulse of finite duration. In the interaction picture built on the exact evolution, the Thomas-Bargmann-Michel-Telegdi equation becomes parallel transport by a connection with constant coefficients on the polarization plane, and the pulse enters only through the closed curve that the transverse vector potential traces there. The net rotation is the holonomy of that connection: an angle about the propagation direction, with the anomaly and twice the signed area enclosed by the curve. That area is the spin angular momentum the pulse carries per unit area, so the rotation measures the helicity of the light. Reduction of the residual dynamics to a rotation coupled through the anomaly alone is an exact result of the 1960s [Ternov, Bagrov, and Klimenko, Sov. Phys. J. 11, 29 (1968); Bagrov and Gitman, The Dirac Equation and its Solutions (De Gruyter, Berlin, 2014), Sec. 5.3], which yields two closed-form cases; the area law is the general second order that those two cases bound. The same area governs the orientation memory of a neutral magnetic dipole [Oblak and Seraj, Phys. Rev. D 109, 044037 (2024)] with a coupling of order unity. For a charged electron on a Volkov orbit the coupling cancels identically, which suppresses the rotation by and leaves a channel with no -independent part. We verify the cancellation at over 180 pulse configurations and the area law over 89 more. Finite focusing restores that part at second order in , and it exceeds the anomalous signal unless at , or at .

    hep-phphysics.acc-phphysics.opticsphysics.plasm-ph0 citations
  13. 13

    Machine Learning is Good for Physics - and Vice Versa

    Michael Krämer🇩🇪 · Tilman Plehn🇩🇪

    Scientific AI is rapidly transforming fundamental physics research and challenging defining aspects of the fundamental physics methodology. We discuss opportunities and dangers of this transformation and find exciting benefits from a close interaction between AI and fundamental physics, provided that we remain aware of the scientific methodologies of the respective fields. For fundamental physics, we discuss two such aspects: statistical validation and a generalizing theory description, both with the goal of discovering new physics in vast datasets.

    hep-ph2 citations
  14. 14

    Descoped and Upscoped FCC-ee Running Scenarios in the SMEFT

    Eugenia Celada🇬🇧 · Elie Hammou🇳🇱 · Jaco ter Hoeve🇬🇧 · Marion O.A. Thomas🇩🇪

    We present projections for the sensitivity to new physics of descoped and upscoped FCC-ee scenarios in the framework of the Standard Model Effective Field Theory (SMEFT). Starting from the baseline FCC-ee programme, we analyse the subsequent impact of, first, removing the top-quark run, then reducing the beam power from 50 MW to 30 MW, and finally removing two interaction points (IPs), in all cases propagating the resulting loss in top-quark mass precision through increased parametric uncertainties. We also analyse the possibility of a staged top-quark run, where the top-quark run is partially restored in case funding becomes available only at a later stage. Motivated by the trade-off between beam power and operational costs, we also consider two upscoped scenarios, either through a uniform increase in luminosity across all energy runs, or through a luminosity enhancement targeting exclusively the top-quark run. We explore the sensitivity and limitations of each scenario and highlight in particular the complementarity between the FCC-ee projections and the (HL)-LHC measurements. By comparing the physics impact of the different running scenarios with the FCC-ee baseline, we show explicitly the importance of the top-quark run, indicating that a substantial fraction of the FCC-ee physics potential depends on it.

    hep-ph0 citations
  15. 16

    Impact of dimension-8 SMEFT operators on baryogenesis via sphaleron decoupling

    Kiyoto Ogawa🇯🇵 · Masanori Tanaka🇨🇳

    We investigate whether a baryogenesis mechanism known as sphalerogenesis can account for the observed baryon asymmetry of the Universe within the Standard Model effective field theory. In this scenario, the baryon asymmetry is generated through the -asymmetric decoupling of electroweak (EW) sphaleron-like transitions. We introduce seven -violating dimension-8 operators constructed from the Higgs doublet and the gauge fields and show that five of them can individually account for the observed baryon asymmetry with satisfying experimental constraints from colliders or electron electric dipole moment measurements. We further study their impact in the presence of a -violating dimension-6 operator. We find that the dimension-8 contributions can be comparable to the dimension-6 contribution when the dimension-8 operators are generated at one loop, demonstrating that loop-order counting can be as important as canonical mass-dimension counting in sphalerogenesis.

    hep-ph0 citations
  16. 17

    Infrared singularities and the collinear limits of multi-leg scattering amplitudes

    Sebastian Jaskiewicz🇨🇭

    Scattering amplitudes admit a factorised structure in special kinematic limits, such as the soft and collinear limits. In this work, we investigate the multi-particle collinear limits of massless amplitudes at high perturbative orders, focusing on the exploration of the mechanisms via which strict collinear factorisation of -particle scattering amplitudes is realised when particles become collinear. We show through four loops that the requirements on the structure of the massless soft anomalous dimension that are imposed by strict collinear factorisation in all two-particle collinear limits are enough to guarantee factorisation also in any multi-particle collinear limit. Demanding that strict collinear factorisation of massless partons is satisfied also for amplitudes that contain a massive coloured particle, we derive new constraints on the soft anomalous dimension by considering the collinear limit of three massless particles.

    hep-ph0 citations
  17. 18

    Tree-Level Factorization Obstruction in Monopole Production

    Hsing-Yi Lai🇺🇸 · John Terning🇺🇸

    We show that the tree-level amplitude for producing a monopole--antimonopole pair from an electrically charged pair cannot be constructed from the minimal one-photon couplings. Gluing the electric and magnetic three-point vertices gives a nonzero photon-pole contribution, but the resulting magnetic final state has the opposite discrete-symmetry eigenvalue from the electric initial state. Local four-point interactions cannot change the pole contribution fixed by the three-point couplings, so they cannot repair this mismatch. For fermions, the obstruction is specific to the minimal three-point coupling: an independent Pauli form factor supplies a spin-singlet three-point amplitude and allows the symmetry selection rule to be satisfied.

    hep-thhep-ph0 citations
  18. 19

    Exact Lattice Identities and Continuum-Limit Dyson--Schwinger Equations for Yang-Mills Theory

    Arpan Chatterjee🇪🇪 · Marco Frasca🇮🇹 · Anish Ghoshal🇬🇧 · Stefan Groote🇪🇪

    Starting from SU(N) on the lattice, we give a rigorous derivation of the Dyson--Schwinger equations in the continuum limit. We formulate the Dyson--Schwinger identities for the lattice Yang--Mills theory directly in terms of the link variables , exploiting the invariance of the Haar measure under left group translations. This provides an exact lattice derivation of the corresponding master equation for the Wilson action, expressed through left-invariant Lie derivatives acting on individual links. Because the construction is carried out directly on the compact gauge group, it avoids the ambiguities associated with introducing Lie-algebra valued gauge potentials as primary integration variables at finite lattice spacing. For practical applications, in a second part we then break down the gauge degree of freedom by choosing Feynman gauge. We analyze the continuum-limit form of the resulting lattice identities and derive equations for the one- and two-point connected functions. Under a further simplifying reduction, these equations close to a tractable scalar system. Our results establish a direct bridge between exact lattice identities and the functional equations commonly used in continuum nonperturbative studies of Yang--Mills theory.

    hep-thhep-lathep-phmath-ph+10 citations
  19. 20

    QCD Chiral Crossover Line from Lee-Yang Edge Singularities

    Heng-Tong Ding🇨🇳 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Kai-Fan Ye🇨🇳

    We propose a universality-based reconstruction of the QCD chiral crossover line from Lee-Yang edge singularities in the complex baryon chemical potential plane. The framework maps lattice-extracted complex Lee-Yang-zero estimates, treated as proxies for edge singularities, to the universal chiral Lee-Yang edge and thereby determines the dependence of both the chiral critical line in the light-quark chiral limit and the pseudo-critical crossover line at physical quark masses. As an illustration, we apply the framework to Lee-Yang-zero estimates recently obtained by the Wuppertal-Budapest collaboration from high-statistics lattice QCD simulations. Without imposing the previously determined small- expansion of the crossover line as input, the reconstructed curvature is consistent with existing continuum lattice-QCD results at small . The fitted chiral-limit transition temperature is also compatible with existing chiral-scaling analyses. These results demonstrate that lattice information on Lee-Yang singularities, combined with universal chiral scaling, provides a quantitatively consistent constraint on the QCD crossover line within the present temperature window and establishes a framework that can be systematically improved with future Lee-Yang-zero determinations.

    hep-lathep-phnucl-exnucl-th0 citations
  20. 21

    Information-Theoretic Black Hole Entropy I: Beyond the Area Law

    Alex Kehagias🇬🇷

    Although the Bekenstein-Hawking area law is consistent with the first and second laws of black hole thermodynamics, it appears to be in conflict with the third law, which in the Nernst formulation states that the entropy should either vanish or approach a universal constant in the zero-temperature limit. We argue that this tension reflects a limitation of the semiclassical area law rather than a fundamental feature of black hole thermodynamics. On this basis, we obtain an entropy formula that is consistent with the third law, and approaches Bekenstein-Hawking entropy in the high-temperature limit. The resulting entropy admits a simple microscopic interpretation, and it can be written as the Kullback-Leibler divergence between a mass-biased Bernoulli distribution and the uniform distribution on N microscopic bits. From this perspective, the thermodynamic black hole entropy admits an information-theoretic representation as an entropy deficit, namely as the relative entropy between the black hole ensemble and a maximally mixed reference ensemble. The Bekenstein-Hawking area law then emerges as the leading term in an expansion, while a universal mass scale , interpreted as an absolute upper bound on the black hole mass, controls the bias of the underlying microscopic ensemble. The subleading terms represent finite-information corrections to the classical area law.

    hep-thgr-qchep-ph0 citations
  21. 22

    Information--Theoretic Black Hole Entropy II: Infrared Gravity and Charged/Rotating Extensions

    Alex Kehagias🇬🇷

    We investigate gravitational and Kerr-Newman extensions of an information-theoretic black-hole entropy that satisfies the Nernst formulation of the third law of thermodynamics. The entropy is identified with the Kullback-Leibler divergence between a mass-dependent Bernoulli ensemble and an unbiased reference ensemble, and therefore measures relative information rather than the logarithm of the number of black-hole microstates. We show perturbatively that its temperature and entropy can be reproduced by an infrared deformation of General Relativity. To linear order in the deformation couplings, the surface-gravity temperature and the Wald entropy agree with the information-theoretic results. In an explicit realization, the matching generates a positive effective cosmological term whose smallness is related to the large microscopic parameter . We also propose an extension to Kerr-Newman black holes based on the irreducible mass. This construction preserves the connection with the horizon area and the semiclassical limit, while distinguishing geometrical extremality from the universal statistical-freezing endpoint, which is independent of angular momentum and charge.

    hep-thgr-qchep-ph0 citations
  22. 23

    AMSB in Truly Confining Gauge Theories

    Riku Ishikawa🇯🇵 · Hitoshi Murayama🇺🇸 · Shota Saito🇯🇵

    We study deformation of supersymmetric -confining (truly confininig) gauge theories with small anomaly mediation of supersymmetry breaking. We identify breaking pattern of global symmetries in the theories. These results can be compared in priciple to lattice simulation of non-supersymmetric theories (except for one of the cases where the theory is pseudoreal and chiral).

    hep-thhep-ph0 citations
  23. 24

    Nonlinear Compton scattering in a quantized pump field

    Kenan Qu🇺🇸

    We develop a fully quantized theory of nonlinear Compton scattering driven by a single-mode quantum field. Exact quantum-Volkov states retain pump depletion, back-action, and final-state correlations through displaced or squeezed-displaced Fock-state ladders. A finite Fock-state pump produces discrete photon-transfer edges and a terminal spectral cutoff. In the bright, weakly depleted regime, the exact theory reduces to a Wigner-function weighted-average of scattering probabilities evaluated at fixed complex field amplitudes, with ordinary and generalized Bessel functions describing the harmonic structure for circular and linear polarization, respectively. For squeezed coherent light, the squeezing angle controls the high-energy emission through photon-number fluctuations.

    quant-phhep-ph0 citations
  24. 25

    The Quantum Mechanics of Rare Events: From Quantum Walks to Stochastic Inflation

    Daniel Green🇺🇸 · Kshitij Gupta🇺🇸 · Akhil Premkumar🇺🇸

    Rare fluctuations in physical systems depend on the detailed microphysics responsible for the fluctuations. In classical statistical systems, the large deviation principle has elucidated the role of semi-classics in describing this regime, and has simultaneously provided a the mathematical foundation of statistical mechanics. Large deviation theory for quantum system is considerably less developed. As all physical systems are fundamentally quantum mechanical, this leaves a major gap in our understanding of rare fluctuations relevant to statistical physics, cosmology, and more. In this paper, we develop the practical aspects of the theory of large deviations relevant for calculating rare events in physical systems from quantum walks to cosmology. We first analyze the case of the anharmonic oscillator coupled to a bath, showing explicitly how the system evolves from dominantly statistical (e.g. thermal) to quantum fluctuations. We then generalize these results, showing that the dominant rare fluctuations minimize the measurement-induced relative entropy. This perspective provides a thermodynamic description of a wide range of open quantum systems. We apply these results to random walks that arise in cosmology through stochastic inflation. We show that the evolution of the density matrix of long wavelength fields on a fixed de Sitter background breaks the KMS symmetry, giving rise to a stationary density matrix that does not respect detailed balance.

    hep-thastro-ph.COgr-qchep-ph+11 citation

Affiliations

first authorsco-authorsvia INSPIRE