ABSTRACT The recent detection of a stochastic gravitational wave background (SGWB) at nanohertz frequencies by pulsar timing arrays (PTAs) has sparked flurry interest. Beyond the standard interpretation that progenitor is network supermassive black hole binaries, many exotic models have also been proposed, some which can potentially offer better fit to data. We explore how various connections between waves (GWs) and cosmic microwave (CMB) spectral distortions (SDs) be leveraged help...

We investigate the low-frequency spectral emission from a network of superconducting cosmic string loops in hopes explaining observed radio synchrotron background. After considering constraints variety astrophysical and cosmological measurements, we identify best-fit solution with tension <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...

ABSTRACT The ARCADE radio excess and EDGES measurement remain puzzling. A link between the two has been previously considered, however, in this work we highlight an important related effect that was not analysed detail before. By performing cosmological thermalization calculations with soft photon injection using cosmotherm, show for 21 cm signal generation, interplay enhanced spectral distortions associated heating can hide a significant before reionization era. We illustrate simple...

Electromagnetic radiation from the cusp region of superconducting cosmic strings leads to a radio excess in photon spectrum early universe and can produce deep absorption feature global 21 cm signal before epoch reionization. We study constraints on parameter space which be derived by demanding that is not larger amplitude than what has recently been reported EDGES collaboration. find previously unconstrained high current, low tension would too strong an feature, are thus ruled out non-detection.

We demonstrate that cosmic string loops may provide a joint resolution of two mysteries surrounding recently observed black holes. For tension in an appropriate range, large radius have the potential to nonlinearities early universe seed supermassive The more numerous smaller can then intermediate mass holes, including those with region between $65\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ and $135\text{ which standard hole formation scenarios predict no holes are able form, but been...

ABSTRACT The observation of quasars at high redshifts presents a mystery in the theory black hole formation. In order to source such objects, one often relies on presence heavy seeds ($M \approx 10^{4-6}{\rm M}_{\odot }$) place early times. Unfortunately, formation these are difficult realize within standard astrophysical context. Here, we investigate whether superconducting cosmic string loops can sufficiently strong overdensities universe address this mystery. We review set direct collapse...

ABSTRACT If they exist, networks of superconducting cosmic strings are capable injecting copious amounts electromagnetic energy into the background over a broad range frequencies. We study this injection both analytically, as well numerically using thermalization code CosmoTherm. With our refined analytic formalism, we update constraints from CMB spectral distortions by following entropy, energy, on amplitude μ-distortion, leading to significant improvement in those limits. Furthermore,...

ABSTRACT The presence of an abundant population low-frequency photons at high redshifts (such as a radio background) can source leading order effects on the evolution matter and spin temperatures through rapid free–free absorptions. This effect, known soft photon heating, have dramatic impact differential brightness temperature, $\Delta T_{\rm b}$, central observable in 21-cm cosmology. Here, we introduce semi-analytic framework to describe dynamics providing simplified set equations useful...

We consider cosmic string cusp annihilations as a possible source of enhancement to the global background radiation temperature in 21-cm photons at reionization. A soft photon spectrum is induced via Bremsstrahlung and Synchrotron emission electrons borne out QCD jets formed off cusp. The maximal energy density comes from synchrotron with tension Gμ ∼ 10−18. In this instance, reionization heated up by 5 · 10−3 K. find that depth absorption trough (δ Tb) altered one part 104 strings,...

The frequency spectrum of the cosmic microwave background (CMB) is a relatively untapped source data which can allow us to peer beyond surface last scattering. Small deviations away from perfect blackbody shape will encode valuable information about state primordial Universe may not be accessible by other means. Here, we briefly review some key science goals CMB spectral distortions, with an emphasis on how future generations experiments used in tandem complementary observational probes...

We explore the possibility that Fast Radio Bursts are due to annihilation of cusps on cosmic string loops. compute energy released in events radio region, expected event rate, and time scale bursts. find rates sufficiently high is small explain current data. predict how rate will change as resolution telescopes improves. Since burst depends tension, future data allow determination tension.

We investigate the low-frequency spectral emission from a network of superconducting cosmic string loops in hopes explaining observed radio synchrotron background. After considering constraints variety astrophysical and cosmological measurements, we identify best-fit solution with tension $G\mu \simeq 6.5 \times 10^{-12}$ current $\mathcal{I} 2.5 10^6$ GeV. This model yields convincing fit to data may be testable near future by distortion (TMS, BISOU) 21 cm experiments (HERA, SKA, REACH)....

The presence of an abundant population low frequency photons at high redshifts (such as a radio background) can source leading order effects on the evolution matter and spin temperatures through rapid free-free absorptions. This effect, known soft photon heating, have dramatic impact differential brightness temperature, $\Delta T_{\rm b}$, central observable in $21$cm cosmology. Here, we introduce semi-analytic framework to describe dynamics providing simplified set equations useful...

Abstract Cosmic string loops are non-linear density fluctuations which form in the early universe and could play an important role explaining many phenomena tension with standard ΛCDM model. Hence, accretion process onto cosmic should be studied detail. Most previous works view as point masses ignore impact of a finite loop size. In this work, we utilize Zel'dovich approximation to calculate mass sourced by static extended time-averaged profile derived from trajectory oscillation, compare...

Spectral distortions of the cosmic microwave background (CMB) provide stringent constraints on energy and entropy production in post-BBN (Big Bang Nucleosynthesis) era. This has been used to constrain dark photon models with COBE/FIRAS forecast potential gains future CMB spectrometers. Here, we revisit these by carefully considering conversion process evolution distortion signal. Previous works only included effect density changes but neglected change number density. We clearly define signal...

ABSTRACT Spectral distortions of the cosmic microwave background (CMB) provide stringent constraints on energy and entropy production in post-BBN (big bang nucleosynthesis) era. This has been used to constrain dark photon models with COBE/FIRAS forecast potential gains future CMB spectrometers. Here, we revisit these by carefully considering conversion process evolution distortion signal. Previous works only included effect density changes but neglected change number density. We clearly...

Axions and axion-like particles (ALPs) remain highly motivated extensions to the standard model due their ability address open questions such as relic abundance of dark matter strong CP problem. are also capable undergoing a resonant mixing with photons when masses two fields roughly equal, producing wide array phenomenological consequences. Here, we revisit constraints coming from conversions cosmic microwave background (CMB) into axions, which will induce distortion frequency spectrum...

If they exist, networks of superconducting cosmic strings are capable injecting copious amounts electromagnetic energy into the background over a broad range frequencies. We study this injection both analytically, as well numerically using thermalization code CosmoTherm. With our refined analytic formalism, we update constraints from CMB spectral distortions by following entropy, energy, on amplitude $\mu$-distortion, leading to significant improvement in those limits. Furthermore, utilize...

ABSTRACT We study the evolution of photon injections with a power-law type spectrum inserted at various epochs universe, and obtain constraints on their parameter space from multiple different cosmological probes. Our work is motivated by realistic possibility having extended spectra astrophysical exotic sources. Going beyond δ-function like approximation, physics becomes richer constraining power probes starts to depend injection history in complex way. As toy model, we first consider...

We compute the energy spectrum of photons {and neutrinos} produced by unwinding a scaling distribution cosmic textures, and discuss implications for high rays, CMB spectral distortions. Textures lead to contribution photon flux which scales as E3 F(E) ∼ E3/2. Hence, tightest constraints on texture model come from highest energies primordial can reach us without being scattered other foregrounds. both μ type y While coming current COBE bounds are weaker than angular power CMB, future surveys...

The ARCADE radio excess and EDGES measurement remain puzzling. A link between the two has been previously considered, however, in this work we highlight an important related effect that was not analyzed detail before. By performing cosmological thermalization calculations with soft photon injection using {\tt CosmoTherm}, show for 21 cm signal generation interplay enhanced spectral distortions associated heating can hide a significant before reionzation era. We illustrate simple power-law...

Cosmic string loops are non-linear density fluctuations which form in the early universe and could play an important role explaining many phenomena tension with standard $\Lambda$CDM model. Hence, details of accretion process onto cosmic should be studied detail. Most previous works view as point masses ignore impact a finite loop size. In this work, we utilize Zel'dovich approximation to calculate mass sourced by static extended time-averaged profile derived from trajectory oscillation,...

We study the evolution of photon injections with a power-law type spectrum inserted at various epochs universe, and obtain constraints on their parameter space from multiple different cosmological probes. Our work is motivated by realistic possibility having extended spectra astrophysical exotic sources. Going beyond $\delta$-function like approximation, physics becomes richer constraining power probes starts to depend injection history in complex way. As toy model, we first consider...