Publications

Order by: publication date number of citations

• Tidal effects in gravitational waves from neutron stars in scalar-tensor theories of gravity

  Gastón Creci, Iris van Gemeren, Tanja Hinderer, Jan Steinhoff

  SciPost Phys. Core 8, 042 (2025) · published 22 May 2025 | Toggle abstract · pdf

  We compute tidal signatures in the gravitational waves (GWs) from neutron star binary inspirals in scalar-tensor gravity, where the dominant adiabatic even-parity tidal interactions involve three types of Love numbers that depend on the matter equation of state and parameters of the gravitational theory. We calculate the modes of the GW amplitudes and the phase evolution in the time and frequency domain, working up to first order in the post-Newtonian and small finite-size approximations. We also perform several case studies to quantify the dipolar and quadrupolar tidal effects and their parameter dependencies specialized to Gaussian couplings. We show that various tidal contributions enter with different signs and scalings with frequency, which generally leads to smaller net tidal GW imprints than for the same binary system in General Relativity.

  4 citations

• The DarkSide-20k TPC and underground argon cryogenic system

  Thomas N. Thorpe on behalf of the DS-20k collaboration

  SciPost Phys. Proc. 12, 069 (2023) · published 5 July 2023 | Toggle abstract · pdf

  DarkSide-20k (DS-20k) will exploit the physical and chemical properties of liquid argon (LAr) housed within a large dual-phase time project chamber (TPC) in its direct search for dark matter. The TPC will utilize a compact, integrated design with many novel features to enable the 20t fiducial volume of underground argon. Underground Argon (UAr) is sourced from underground CO$_2$ wells and depleted in the radioactive isotope $^{39}$Ar, greatly enhancing the experimental sensitivity to dark matter interactions. Sourcing and transporting the $\mathcal{O}$(100t) of UAr for (DS-20k) is costly, and a dedicated single-closed-loop cryogenic system has been designed, constructed, and tested to handle the valuable UAr. We present an overview of the (DS-20k) TPC design and the first results from the UAr cryogenic system.

  4 citations

• Underground laboratories

  Aldo Ianni

  SciPost Phys. Proc. 12, 007 (2023) · published 3 July 2023 | Toggle abstract · pdf

  A brief review on underground laboratories at the time of IDM 2022 is reported. General characteristics of these research infrastructures are discussed and a few highlights from different laboratories are reported. The idea of networking between underground laboratories is discussed.

  4 citations

• Conformal field theories on deformed spheres, anomalies, and supersymmetry

  Joseph A. Minahan, Usman Naseer, Charles Thull

  SciPost Phys. 10, 063 (2021) · published 10 March 2021 | Toggle abstract · pdf

  We study the free energy of four-dimensional CFTs on deformed spheres. For generic nonsupersymmetric CFTs only the coefficient of the logarithmic divergence in the free energy is physical, which is an extremum for the round sphere. We then specialize to $\mathcal{N}=2$ SCFTs where one can preserve some supersymmetry on a compact manifold by turning on appropriate background fields. For deformations of the round sphere the $c$ anomaly receives corrections proportional to the supersymmetric completion of the (Weyl)$^2$ term, which we determine up to one constant by analyzing the scale dependence of various correlators in the stress-tensor multiplet. We further show that the double derivative of the free energy with respect to the marginal couplings is proportional to the two-point function of the bottom components of the marginal chiral multiplet placed at the two poles of the deformed sphere. We then use anomaly considerations and counter-terms to parametrize the finite part of the free energy which makes manifest its dependence on the K\"ahler potential. We demonstrate these results for a theory with a vector multiplet and a massless adjoint hypermultiplet using results from localization. Finally, by choosing a special value of the hypermultiplet mass where the free energy is independent of the deformation, we derive an infinite number of constraints between various integrated correlators in $\mathcal{N}=4$ super Yang-Mills with any gauge group and at all values of the coupling, extending previous results.

  4 citations

• Nonlinearity of transparent SNS weak links decreases sharply with length

  Valla Fatemi, Pavel D. Kurilovich, Anton R. Akhmerov, Bernard van Heck

  SciPost Phys. 18, 091 (2025) · published 12 March 2025 | Toggle abstract · pdf

  Superconductor-normal material-superconductor (SNS) junctions are being integrated into microwave circuits for fundamental and applied research goals. The short junction limit is a common simplifying assumption for experiments with SNS junctions, but this limit constrains how small the nonlinearity of the microwave circuit can be. Here, we show that a finite length of the weak link strongly suppresses the nonlinearity compared to its zero-length limit -- the suppression can be up to a factor of ten even when the length remains shorter than the induced coherence length. We tie this behavior to the nonanalytic dependence of nonlinearity on length, which the critical current does not exhibit. Further, we identify additional experimentally observable consequences of nonzero length, and we conjecture that anharmonicity is bounded between zero and a maximally negative value for any non-interacting Josephson junction in the presence of time-reversal symmetry. We promote SNS junction length as a useful parameter for designing weakly nonlinear microwave circuits.

  4 citations

• Out-of-equilibrium full counting statistics in Gaussian theories of quantum magnets

  Riccardo Senese, Jacob H. Robertson, Fabian H. L. Essler

  SciPost Phys. 17, 139 (2024) · published 20 November 2024 | Toggle abstract · pdf

  We consider the probability distributions of the subsystem (staggered) magnetization in ordered and disordered models of quantum magnets in D dimensions. We focus on Heisenberg antiferromagnets and long-range transverse-field Ising models as particular examples. By employing a range of self-consistent time-dependent mean-field approximations in conjunction with Holstein-Primakoff, Dyson-Maleev, Schwinger boson and modified spin-wave theory representations we obtain results in thermal equilibrium as well as during non-equilibrium evolution after quantum quenches. To extract probability distributions we derive a simple formula for the characteristic function of generic quadratic observables in any Gaussian theory of bosons.

  4 citations

• Chaos in the vicinity of a singularity in the three-body problem: The equilateral triangle experiment in the zero angular momentum limit

  Hugo D. Parischewsky, Alessandro A. Trani, Nathan W. C. Leigh

  SciPost Phys. Core 6, 016 (2023) · published 21 March 2023 | Toggle abstract · pdf

  We present numerical simulations of the gravitational three-body problem, in which three particles lie at rest close to the vertices of an equilateral triangle. In the unperturbed problem, the three particles fall towards the center of mass of the system to form a three-body collision, or singularity, where the particles overlap in space and time. By perturbing the initial positions of the particles, we are able to study chaos in the vicinity of the singularity. Here we cover both the singular region close to the unperturbed configuration and the binary-single scattering regime where one side of the triangle is very short compared to the other two. We make phase space plots to study the regular and ergodic subsets of our simulations and compare them with the outcomes expected from the statistical escape theory of the three-body problem. We further provide fits to the ergodic subset to characterize the properties of the left-over binaries. We identify the discrepancy between the statistical theory and the simulations in the regular subset of interactions, which only exhibits weak chaos. As we decrease the scale of the perturbations in the initial positions, the phase space becomes entirely dominated by regular interactions, according to our metric for chaos. Finally, we show the effect of general relativity corrections by simulating the same scenario with the inclusion of post-Newtonian corrections to the equations of motion.

  4 citations

• A path integral ground state Monte Carlo algorithm for entanglement of lattice bosons

  Emanuel Casiano-Diaz, C. M. Herdman, Adrian Del Maestro

  SciPost Phys. 14, 054 (2023) · published 29 March 2023 | Toggle abstract · pdf

  A ground state path integral quantum Monte Carlo algorithm is introduced that allows for the study of entanglement in lattice bosons at zero temperature. The Rényi entanglement entropy between spatial subregions is explored across the phase diagram of the one dimensional Bose-Hubbard model for systems consisting of up to $L=256$ sites at unit-filling without any restrictions on site occupancy, far beyond the reach of exact diagonalization. The favorable scaling of the algorithm is demonstrated through a further measurement of the Rényi entanglement entropy at the two dimensional superfluid-insulator critical point for large system sizes, confirming the existence of the expected entanglement boundary law in the ground state. The Rényi estimator is extended to measure the symmetry resolved entanglement that is operationally accessible as a resource for experimentally relevant lattice gases with fixed total particle number.

  4 citations

• Dipole symmetries from the topology of the phase space and the constraints on the low-energy spectrum

  Tomáš Brauner, Naoki Yamamoto, Ryo Yokokura

  SciPost Phys. 16, 051 (2024) · published 20 February 2024 | Toggle abstract · pdf

  We demonstrate the general existence of a local dipole conservation law in bosonic field theory. The scalar charge density arises from the symplectic form of the system, whereas the tensor current descends from its stress tensor. The algebra of spatial translations becomes centrally extended in presence of field configurations with a finite nonzero charge. Furthermore, when the symplectic form is closed but not exact, the system may, surprisingly, lack a well-defined momentum density. This leads to a theorem for the presence of additional light modes in the system whenever the short-distance physics is governed by a translationally invariant local field theory. We also illustrate this mechanism for axion electrodynamics as an example of a system with Nambu-Goldstone modes of higher-form symmetries.

  4 citations

• Quantum-critical properties of the one- and two-dimensional random transverse-field Ising model from large-scale quantum Monte Carlo simulations

  Calvin Krämer, Jan Alexander Koziol, Anja Langheld, Max Hörmann, Kai Phillip Schmidt

  SciPost Phys. 17, 061 (2024) · published 23 August 2024 | Toggle abstract · pdf

  We study the ferromagnetic transverse-field Ising model with quenched disorder at $T = 0$ in one and two dimensions by means of stochastic series expansion quantum Monte Carlo simulations using a rigorous zero-temperature scheme. Using a sample-replication method and averaged Binder ratios, we determine the critical shift and width exponents $\nu_\mathrm{s}$ and $\nu_\mathrm{w}$ as well as unbiased critical points by finite-size scaling. Further, scaling of the disorder-averaged magnetisation at the critical point is used to determine the order-parameter critical exponent $\beta$ and the critical exponent $\nu_{\mathrm{av}}$ of the average correlation length. The dynamic scaling in the Griffiths phase is investigated by measuring the local susceptibility in the disordered phase and the dynamic exponent $z'$ is extracted. By applying various finite-size scaling protocols, we provide an extensive and comprehensive comparison between the different approaches on equal footing. The emphasis on effective zero-temperature simulations resolves several inconsistencies in existing literature.

  4 citations