Some properties of renormalons in gauge theories

We find the explicit operatorial form of renormalon-type singularities in abelian gauge theory. Local operators of dimension six take care of the first U.V. renormalon, non local operators are needed for I.R. singularities. In the effective lagrangian constructed with these operators non local imaginary parts appearing in the usual perturbative expansion at large orders are cancelled.Comment: 17 pages + uuencoded file with 7 figures, REVTeX, IFUP-TH-31-9

Condensation of vortices and disorder parameter in 3d Heisenberg model

The 3d Heisenberg model is studied from a dual point of view. It is shown that the disordered phase corresponds to condensation of vortices in the vacuum, and the critical indices are computed from the corresponding disorder parameter.Comment: LATTICE98(spin

Dual vortices in Abelian projected SU(2) in the Polyakov gauge

We study dual Abrikosov vortices in Abelian projected SU(2) gauge theory in the Polyakov gauge. We show that vortices are present in this gauge but they are suppressed with respect to the maximal Abelian gauge. We interpret this difference in terms of the shielding of the electric charge by the charged coset fields.Comment: Talk presented at LATTICE96(topology), 3 pages, latex, 4 eps figures, uses epsfig and espcrc2.sty (included

A disorder parameter for dual superconductivity in gauge theories

Dual superconductivity in the confining phase of gauge theories is discussed in terms of a disorder parameter which vanishes in normal phase and is different from zero in the superconducting phase.Comment: 3 pages, 4 postscript figures, espcrc2, epsfig latex styles, Contribution to Lat 97 Conference, Edinburg

Condensation of vortices in the X-Y model in 3d: a disorder parameter

A disorder parameter is constructed which signals the condensation of vortices. The construction is tested by numerical simulations.Comment: 9 pages, 5 postscript figures, typset using REVTE

HERMES: Gamma-ray burst and gravitational wave counterpart hunter

Gamma-ray bursts (GRBs) bridge relativistic astrophysics and multimessenger astronomy. Space–based γ- and X-ray wide-field detectors have proven essential for detecting and localizing the highly variable GRB prompt emission, which is also a counterpart of gravitational wave events. We studied the capability of detecting long and short GRBs with the High Energy Rapid Modular Ensemble of Satellites (HERMES) Pathfinder (HP) and SpIRIT, namely a swarm of six 3U CubeSats to be launched in early 2025, and a 6U CubeSat launched on December 1 2023. We also studied the capabilities of two advanced configurations of swarms of more than eight satellites with improved detector performances (HERMES Constellations). The HERMES detectors, sensitive down to ∼2–3 keV, will be able to detect faint and soft GRBs, which comprise X-ray flashes and high-redshift bursts. By combining state-of-the-art long- and short-GRB population models with a description of the single module performance, we estimate that HP will detect ∼195+−2221 long GRBs (3.4+−0038 at redshift z > 6) and ∼19+−53 short GRBs per year. The larger HERMES Constellations under study can detect between ∼1300 and ∼3000 long GRBs per year and between ∼160 and ∼400 short GRBs per year, depending on the chosen configuration, with a rate of long GRBs above z > 6 of between 30 and 75 per year. Finally, we explored the capability of HERMES to detect short GRBs as electromagnetic counterparts of binary neutron star (BNS) mergers detected as gravitational signals by current and future ground–based interferometers. Under the assumption that the GRB jets are structured, we estimate that HP can provide up to ∼1 (14) yr−1 joint detections during the fifth LIGO–Virgo–KAGRA observing run (Einstein Telescope single triangle 10 km arm configuration). These numbers become ∼4 (100) yr−1, respectively, for the HERMES Constellation configuration