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It has been suggested that cosmological dark matter may include a population of vortons (meaning small centrifugally stabilised cosmic string loops) as an outcome of (non-standard) electroweak symmetry breaking. The implications for this…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. Carter

Using a modification of the Zel'dovich approximation adapted to hot dark matter, the accretion of such matter onto moving cosmic string loops is studied. It is shown that a large number of $10^{12}M_\odot$ nonlinear objects will be produced…

Astrophysics · Physics 2015-06-24 R. Moessner , R. Brandenberger

We show that the existence of cosmic strings can be strongly constrained by the next generation of gravitational lensing surveys at radio frequencies. We focus on cosmic string loops, which simulations suggest would be far more numerous…

Astrophysics · Physics 2008-11-26 Katherine J. Mack , Daniel H. Wesley , Lindsay J. King

We find the constraints from WMAP and SDSS data on the fraction of cosmological fluctuations sourced by local cosmic strings using a Markov Chain Monte Carlo (MCMC) analysis. In addition to varying the usual 6 cosmological parameters and…

Astrophysics · Physics 2014-10-13 Mark Wyman , Levon Pogosian , Ira Wasserman

We exploit the techniques of dynamical systems to study the cosmological evolution of cosmic fundamental strings and effective strings arising from branes wrapped on internal cycles. We also include the whole potential of the volume modulus…

High Energy Physics - Theory · Physics 2026-04-01 Luca Brunelli , Michele Cicoli , Francisco Gil Pedro

We demonstrate that cosmic string loops may provide a joint resolution of two mysteries surrounding recently observed black holes. For a string tension in an appropriate range, large radius string loops have the potential to provide the…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Robert Brandenberger , Bryce Cyr , Hao Jiao

Cosmic strings have gained a great interest, since they are formed in a large class of brane inflationary models. The most interesting story is that cosmic strings in brane models are distinguished in future cosmological observations. If…

High Energy Physics - Phenomenology · Physics 2009-11-11 Tomohiro Matsuda

Primordial black holes (PBHs) formed in the early Universe can accret dark matter particles due to gravity and form ultracompact minihalos (UCMHs). The theoretical researches and simulations have shown that the density profile of dark…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-08 Yupeng Yang

We consider the possibility of formation of cosmic strings with black holes as beads. We focus on the simplest setup where two black holes are formed on a long cosmic string. It turns out the in absence of a background magnetic field and…

High Energy Physics - Theory · Physics 2014-11-06 Amjad Ashoorioon , Robert B. Mann

Recent work by Jenkins and Sakellariadou claims that cusps on cosmic strings lead to black hole production. To derive this conclusion they use the hoop conjecture in the rest frame of the string loop, rather than in the rest frame of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-14 Jose J. Blanco-Pillado , Ken D. Olum , Alexander Vilenkin

Cosmic string loops contain cusps which decay by emitting bursts of particles. A significant fraction of the released energy is in the form of photons. These photons are injected non-thermally and can hence cause spectral distortions of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-23 Madeleine Anthonisen , Robert Brandenberger , Alex Laguë , Ian A. Morrison , Daixi Xia

In this work the equation of circular loops of cosmic string possessing time-dependent tension is studied in the de Sitter spacetime. We find that the cosmic string loops with initial radius $r(t_{0})>0.707L$, L de Sitter radius, should not…

High Energy Physics - Theory · Physics 2009-03-24 Yunqi Liu , Hongbo Cheng

We present observation of large, expanding string loops forming around a heated wire tip embedded in a nematic liquid crystal sample. Loops expand due to convective stretching. This observation leads to a new insight into phenomena which…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ajit M. Srivastava

The local environment is ideal for searching out compact dark structures via the microlensing and multi-frequency emissions as these objects are expected to be faint and microlensing experiments have already hinted at their possibility. In…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-16 Geoff Beck , Sergio Colafrancesco

We discuss data analysis techniques that can be used in the search for gravitational wave bursts from cosmic strings. When data from multiple interferometers are available, we describe consistency checks that can be used to greatly reduce…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Xavier Siemens , Jolien Creighton , Irit Maor , Saikat Ray Majumder , Kipp Cannon , Jocelyn Read

It has been speculated that cosmic string networks could produce ultra-high energy cosmic rays as a by-product of their evolution. By making use of recent work on the evolution of such networks, it will be shown that the flux of cosmic rays…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. J. Gill , T. W. B. Kibble

In this paper, we study the equation of circular loops with time-dependant tension in the BTZ black hole background. We obtain various cases where cosmic string loops finally collapse to form black holes. Also, we study effect of the BTZ…

High Energy Physics - Theory · Physics 2011-08-24 J. Sadeghi , H. M. Farahani , B. Pourhassan , S. M. Noorbakhsh

In this paper the equation of circular loops of cosmic string with periodic tension is investigated in the Minkowski spacetime and Robertson-Walker universe respectively. We find that the cosmic string loops possessing this kind of…

High Energy Physics - Theory · Physics 2015-06-05 Leilin Wang , Hongbo Cheng

We analytically derive the expected number density distribution of Nambu-Goto cosmic string loops at any redshift soon after the time of string formation to today. Our approach is based on the Polchinski-Rocha model of loop formation from…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-21 Larissa Lorenz , Christophe Ringeval , Mairi Sakellariadou

In the dark age of the universe, any exotic sources, e.g. the dark matter annihilation, which inject the energy into the intergalactic medium (IGM) will left some imprint on the 21cm background signal. Recently, one new kind of dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Yupeng Yang