This research aims to provide the geometrical foundation of the uncertainty principle within a new causal structure of spacetime so-called Symmetrical Special Relativity (SSR), where there emerges a Lorentz violation due to the presence of an invariant minimum speed $V$ related to the vacuum energy. SSR predicts that a dS-scenario occurs only for a certain regime of speeds $v$, where $v0$. For $v=v_0$, Minkowski (pseudo-Euclidian) space is recovered for representing the flat space ($Lambda=0$), and for $v>v_0$ ($Phi>0$), Anti-de Sitter (AdS) scenario prevails ($Lambda<0$). The fact that the current universe is flat as its average density of matter distribution ($rho_m$ given for a slightly negative curvature $R$) coincides with its vacuum energy density ($rho_{Lambda}$ given for a slightly positive curvature $Lambda$), i.e., the {it cosmic coincidence problem}, is now addressed by SSR. SSR provides its energy-momentum tensor of perfect fluid, leading to the EOS of vacuum ($p=-rho_{Lambda}$). Einstein equation for vacuum given by such SSR approach allows us to obtain $rho_{Lambda}$ associated with a scalar curvature $Lambda$, whereas the solution of Einstein equation only in the presence of a homogeneous distribution of matter $rho_m$ for the whole universe presents a scalar curvature $R$, in such a way that the presence of the background field $Lambda$ opposes the Riemannian curvature $R$, thus leading to a current effective curvature $R_{eff}=R+Lambdaapprox 0$ according to observations.
{"title":"Lorentz violation with an invariant minimum speed as foundation of the uncertainty principle in Minkowski, dS and AdS spaces","authors":"Cláudio Nassif Cruz","doi":"arxiv-2409.04925","DOIUrl":"https://doi.org/arxiv-2409.04925","url":null,"abstract":"This research aims to provide the geometrical foundation of the uncertainty\u0000principle within a new causal structure of spacetime so-called Symmetrical\u0000Special Relativity (SSR), where there emerges a Lorentz violation due to the\u0000presence of an invariant minimum speed $V$ related to the vacuum energy. SSR\u0000predicts that a dS-scenario occurs only for a certain regime of speeds $v$,\u0000where $v<v_0=sqrt{cV}$, which represents the negative gravitational potentials\u0000($Phi<0$) connected to the cosmological parameter $Lambda>0$. For $v=v_0$,\u0000Minkowski (pseudo-Euclidian) space is recovered for representing the flat space\u0000($Lambda=0$), and for $v>v_0$ ($Phi>0$), Anti-de Sitter (AdS) scenario\u0000prevails ($Lambda<0$). The fact that the current universe is flat as its\u0000average density of matter distribution ($rho_m$ given for a slightly negative\u0000curvature $R$) coincides with its vacuum energy density ($rho_{Lambda}$ given\u0000for a slightly positive curvature $Lambda$), i.e., the {it cosmic coincidence\u0000problem}, is now addressed by SSR. SSR provides its energy-momentum tensor of\u0000perfect fluid, leading to the EOS of vacuum ($p=-rho_{Lambda}$). Einstein\u0000equation for vacuum given by such SSR approach allows us to obtain\u0000$rho_{Lambda}$ associated with a scalar curvature $Lambda$, whereas the\u0000solution of Einstein equation only in the presence of a homogeneous\u0000distribution of matter $rho_m$ for the whole universe presents a scalar\u0000curvature $R$, in such a way that the presence of the background field\u0000$Lambda$ opposes the Riemannian curvature $R$, thus leading to a current\u0000effective curvature $R_{eff}=R+Lambdaapprox 0$ according to observations.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In both general relativity and Lanczos-Lovelock theories of gravity, it has been found that the Noether charge density in any bulk region of spacetime can be interpreted as the heat content of the boundary surface. In addition, it was found that the dynamical evolution of spacetime can be interpreted as the departure from an ``equipartition" between properly defined bulk and surface degrees of freedom. We find that the same interpretations are valid for scalar-tensor theories of gravity, in which case the gravity is mediated by the metric tensor as well as by the scalar field. Moreover, these results hold in both the frames associated with the scalar-tensor theory, namely the Jordan and the Einstein frames. However, it turns out that there are two dynamically equivalent representations of the scalar-tensor theory in the Jordan frame, differing by total derivatives in the action, which are thermodynamically inequivalent. Thus thermodynamics is sensitive to various representations of scalar-tensor theories. This not only implies the robustness of the thermodynamic description of gravity beyond general relativity, but also depicts the importance of having a thermodynamic description by distinguishing various dynamically equivalent representations.
{"title":"Scalar-tensor theories of gravity from a thermodynamic viewpoint","authors":"Krishnakanta Bhattacharya, Sumanta Chakraborty","doi":"arxiv-2409.04176","DOIUrl":"https://doi.org/arxiv-2409.04176","url":null,"abstract":"In both general relativity and Lanczos-Lovelock theories of gravity, it has\u0000been found that the Noether charge density in any bulk region of spacetime can\u0000be interpreted as the heat content of the boundary surface. In addition, it was\u0000found that the dynamical evolution of spacetime can be interpreted as the\u0000departure from an ``equipartition\" between properly defined bulk and surface\u0000degrees of freedom. We find that the same interpretations are valid for\u0000scalar-tensor theories of gravity, in which case the gravity is mediated by the\u0000metric tensor as well as by the scalar field. Moreover, these results hold in\u0000both the frames associated with the scalar-tensor theory, namely the Jordan and\u0000the Einstein frames. However, it turns out that there are two dynamically\u0000equivalent representations of the scalar-tensor theory in the Jordan frame,\u0000differing by total derivatives in the action, which are thermodynamically\u0000inequivalent. Thus thermodynamics is sensitive to various representations of\u0000scalar-tensor theories. This not only implies the robustness of the\u0000thermodynamic description of gravity beyond general relativity, but also\u0000depicts the importance of having a thermodynamic description by distinguishing\u0000various dynamically equivalent representations.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142225610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We put forward a primordial scenario to alleviate cosmological tensions, i.e. Hubble ($H_0$) tension and $ S_8 $ tension. Based on flat $Lambda$CDM, the Bounce-Inflation (BI) scenario gives the results that $ H_0 = 68.60^{+0.40}_{-0.45} , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.806 pm 0.011 $ by using texttt{Planck 2018} data sets and $ H_0 = 68.96 pm 0.38 , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.797pm 0.010 $ by using texttt{Planck 2018} + texttt{SPT3G} data sets. These reduce the cosmological tensions slightly. We also take an extended $Lambda$CDM model into account, $Lambda$CDM (BI)+$A_L$, where $ A_L $ is the gravitational lensing amplitude. The results are $ H_0 = 69.38 pm 0.49 , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.774 pm 0.014 $ fitted by texttt{Planck 2018} data sets and $ H_0 = 69.49 pm 0.45 , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.771^{+0.013}_{-0.012} $ fitted by texttt{Planck 2018} + texttt{SPT3G} data sets, which reduce the Hubble tension to $sim 3sigma $ level and show no $S_8 $ tension. The $A_L approx 1.1$ is smaller than the result of the inflation scenario with a constraint of texttt{Planck 2018} data sets. Besides, the spectral index of the bounce-inflation scenario $ n_s $ is about $ 0.98 $, with a trend to the Harrison-Zel'dovich spectrum.
{"title":"Primordial Bounce-Inflation Scenario to Alleviate Cosmological Tensions and Lensing Anomaly","authors":"Hao-Hao Li, Xin-zhe Zhang, Taotao Qiu","doi":"arxiv-2409.04027","DOIUrl":"https://doi.org/arxiv-2409.04027","url":null,"abstract":"We put forward a primordial scenario to alleviate cosmological tensions, i.e.\u0000Hubble ($H_0$) tension and $ S_8 $ tension. Based on flat $Lambda$CDM, the\u0000Bounce-Inflation (BI) scenario gives the results that $ H_0 =\u000068.60^{+0.40}_{-0.45} , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.806 pm\u00000.011 $ by using texttt{Planck 2018} data sets and $ H_0 = 68.96 pm 0.38 ,\u0000text{km}/text{s}/text{Mpc}$, $ S_8 = 0.797pm 0.010 $ by using\u0000texttt{Planck 2018} + texttt{SPT3G} data sets. These reduce the cosmological\u0000tensions slightly. We also take an extended $Lambda$CDM model into account,\u0000$Lambda$CDM (BI)+$A_L$, where $ A_L $ is the gravitational lensing amplitude.\u0000The results are $ H_0 = 69.38 pm 0.49 , text{km}/text{s}/text{Mpc}$, $ S_8\u0000= 0.774 pm 0.014 $ fitted by texttt{Planck 2018} data sets and $ H_0 = 69.49\u0000pm 0.45 , text{km}/text{s}/text{Mpc}$, $ S_8 = 0.771^{+0.013}_{-0.012} $\u0000fitted by texttt{Planck 2018} + texttt{SPT3G} data sets, which reduce the\u0000Hubble tension to $sim 3sigma $ level and show no $S_8 $ tension. The $A_L\u0000approx 1.1$ is smaller than the result of the inflation scenario with a\u0000constraint of texttt{Planck 2018} data sets. Besides, the spectral index of\u0000the bounce-inflation scenario $ n_s $ is about $ 0.98 $, with a trend to the\u0000Harrison-Zel'dovich spectrum.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"671 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mass transfer process is prevalent during the inspiral phase of compact binary systems. Our study focuses on systems comprising low-mass white dwarfs, particularly in neutron star-white dwarf binaries and double white dwarf binaries, where a stable mass transfer process occurs at low frequencies. By analyzing the evolution of gravitational wave frequencies in the presence of mass transfer within quasi-circular orbits, we derive an analytical expression for the time-dependent frequency across different frequency bands and the waveforms emitted by compact binaries. Considering gravitational waves emitted by compact binaries in the $1thicksim10$ mHz band, based on the Fisher analysis, we find that the mass transfer rate can be measured as accurately as $10^{-7} M_odot/text{year}$ by space-based gravitational-wave detectors with a signal-to-noise ratio of the order of $10^3$. Including the mass transfer effect in the waveforms provides a new possibility to measure the individual masses of double white dwarf binaries. The relative error of measured white dwarf masses can be down to the order of $0.01$.
{"title":"Gravitational wave signatures and detectability of the mass transfer effect in compact binaries","authors":"Zi-Han Zhang, Tan Liu, Shenghua Yu, Zong-Kuan Guo","doi":"arxiv-2409.04020","DOIUrl":"https://doi.org/arxiv-2409.04020","url":null,"abstract":"The mass transfer process is prevalent during the inspiral phase of compact\u0000binary systems. Our study focuses on systems comprising low-mass white dwarfs,\u0000particularly in neutron star-white dwarf binaries and double white dwarf\u0000binaries, where a stable mass transfer process occurs at low frequencies. By\u0000analyzing the evolution of gravitational wave frequencies in the presence of\u0000mass transfer within quasi-circular orbits, we derive an analytical expression\u0000for the time-dependent frequency across different frequency bands and the\u0000waveforms emitted by compact binaries. Considering gravitational waves emitted\u0000by compact binaries in the $1thicksim10$ mHz band, based on the Fisher\u0000analysis, we find that the mass transfer rate can be measured as accurately as\u0000$10^{-7} M_odot/text{year}$ by space-based gravitational-wave detectors with\u0000a signal-to-noise ratio of the order of $10^3$. Including the mass transfer\u0000effect in the waveforms provides a new possibility to measure the individual\u0000masses of double white dwarf binaries. The relative error of measured white\u0000dwarf masses can be down to the order of $0.01$.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigate the physical behaviour of a stellar configuration by developing a compact stellar model within the framework of $f(Q)$ gravity. We study the mass-radius ($M-R$) relationship and obtain the maximum compactness bound of the resultant stellar configuration by assuming the modification to be linear in non-metricity $Q$, i.e. $f(Q) = alpha Q + beta$. The maximum compactness bound proposed in $f(Q)$ gravity is analogous to the Buchdahl bound in general relativity. We note that the compactness bound increases in $f(Q)$ gravity. In the general relativistic limit ($alpha=-1$), our approach regains the Buchdahl bound for an incompressible star. Our observation might be relevant in the context of a recent observation with the MeerKAT observatory, which indicates the existence of high mass non-black hole compact objects which cannot be modelled by using the conventional neutron star equation of state (EoS).
{"title":"Physical properties and the maximum compactness bound of a class of compact stars in $f(Q)$ gravity","authors":"R. Sharma, A. Ghosh, A. Paul","doi":"arxiv-2409.04487","DOIUrl":"https://doi.org/arxiv-2409.04487","url":null,"abstract":"We investigate the physical behaviour of a stellar configuration by\u0000developing a compact stellar model within the framework of $f(Q)$ gravity. We\u0000study the mass-radius ($M-R$) relationship and obtain the maximum compactness\u0000bound of the resultant stellar configuration by assuming the modification to be\u0000linear in non-metricity $Q$, i.e. $f(Q) = alpha Q + beta$. The maximum\u0000compactness bound proposed in $f(Q)$ gravity is analogous to the Buchdahl bound\u0000in general relativity. We note that the compactness bound increases in $f(Q)$\u0000gravity. In the general relativistic limit ($alpha=-1$), our approach regains\u0000the Buchdahl bound for an incompressible star. Our observation might be\u0000relevant in the context of a recent observation with the MeerKAT observatory,\u0000which indicates the existence of high mass non-black hole compact objects which\u0000cannot be modelled by using the conventional neutron star equation of state\u0000(EoS).","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"135 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present work presents analytically constructed equilibrium structures of charged perfect fluids orbiting Kerr Black holes embedded in an asymptotically uniform magnetic field. Our focus is on the effect of the non-constant angular momentum distribution through the disk, as well as its combined effect with the external magnetic field and the fluid charge. We demonstrate that the three parameters of our study have a significant impact on the various features of the accretion disk: the shape, the size of the disk and the characteristic of the fluid, as the pressure and the rest-mass density. Through our investigation, we observe substantial deviations from both the uncharged thick disk model and the charged disk model with constant angular momentum.
{"title":"Equilibrium of charged fluid around a Kerr black hole immersed in a magnetic field: variation of angular momentum","authors":"Audrey Trova","doi":"arxiv-2409.04170","DOIUrl":"https://doi.org/arxiv-2409.04170","url":null,"abstract":"The present work presents analytically constructed equilibrium structures of\u0000charged perfect fluids orbiting Kerr Black holes embedded in an asymptotically\u0000uniform magnetic field. Our focus is on the effect of the non-constant angular\u0000momentum distribution through the disk, as well as its combined effect with the\u0000external magnetic field and the fluid charge. We demonstrate that the three\u0000parameters of our study have a significant impact on the various features of\u0000the accretion disk: the shape, the size of the disk and the characteristic of\u0000the fluid, as the pressure and the rest-mass density. Through our\u0000investigation, we observe substantial deviations from both the uncharged thick\u0000disk model and the charged disk model with constant angular momentum.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lina Zhang, Qiyuan Pan, Bo Liu, Ming Zhang, De-Cheng Zou
In this paper, we focus on massive Einstein-dilaton gravity including the coupling of dilaton scalar field to massive graviton terms, and then derive static and spherically symmetric solutions of charged dilatonic black holes in four dimensional spacetime. We find that the dilatonic black hole could possess different horizon structures for some suitably parameters. Then, we also investigate the thermodynamic properties of charged dilatonic black holes where $f(r)$ approaches $+infty$ and $-infty$, respectively.
{"title":"Charged dilatonic black holes in dilaton-massive gravity","authors":"Lina Zhang, Qiyuan Pan, Bo Liu, Ming Zhang, De-Cheng Zou","doi":"arxiv-2409.04485","DOIUrl":"https://doi.org/arxiv-2409.04485","url":null,"abstract":"In this paper, we focus on massive Einstein-dilaton gravity including the\u0000coupling of dilaton scalar field to massive graviton terms, and then derive\u0000static and spherically symmetric solutions of charged dilatonic black holes in\u0000four dimensional spacetime. We find that the dilatonic black hole could possess\u0000different horizon structures for some suitably parameters. Then, we also\u0000investigate the thermodynamic properties of charged dilatonic black holes where\u0000$f(r)$ approaches $+infty$ and $-infty$, respectively.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hector Villarrubia-Rojo, Stefano Savastano, Miguel Zumalacárregui, Lyla Choi, Srashti Goyal, Liang Dai, Giovanni Tambalo
Wave-optics phenomena in gravitational lensing occur when the signal's wavelength is commensurate to the gravitational radius of the lens. Although potentially detectable in lensed gravitational waves, fast radio bursts and pulsars, accurate numerical predictions are challenging to compute. Here we present novel methods for wave-optics lensing that allow the treatment of general lenses. In addition to a general algorithm, specialized methods optimize symmetric lenses (arbitrary number of images) and generic lenses in the single-image regime. We also develop approximations for simple lenses (point-like and singular isothermal sphere) that drastically outperform known solutions without compromising accuracy. These algorithms are implemented in Gravitational Lensing of Waves (GLoW): an accurate, flexible, and fast code. GLoW efficiently computes the frequency-dependent amplification factor for generic lens models and arbitrary impact parameters in O(1 ms) to O(10 ms) depending on the lens configuration and complexity. GLoW is readily applicable to model lensing diffraction on gravitational-wave signals, offering new means to investigate the distribution of dark-matter and large-scale structure with signals from ground and space detectors.
{"title":"GLoW: novel methods for wave-optics phenomena in gravitational lensing","authors":"Hector Villarrubia-Rojo, Stefano Savastano, Miguel Zumalacárregui, Lyla Choi, Srashti Goyal, Liang Dai, Giovanni Tambalo","doi":"arxiv-2409.04606","DOIUrl":"https://doi.org/arxiv-2409.04606","url":null,"abstract":"Wave-optics phenomena in gravitational lensing occur when the signal's\u0000wavelength is commensurate to the gravitational radius of the lens. Although\u0000potentially detectable in lensed gravitational waves, fast radio bursts and\u0000pulsars, accurate numerical predictions are challenging to compute. Here we\u0000present novel methods for wave-optics lensing that allow the treatment of\u0000general lenses. In addition to a general algorithm, specialized methods\u0000optimize symmetric lenses (arbitrary number of images) and generic lenses in\u0000the single-image regime. We also develop approximations for simple lenses\u0000(point-like and singular isothermal sphere) that drastically outperform known\u0000solutions without compromising accuracy. These algorithms are implemented in\u0000Gravitational Lensing of Waves (GLoW): an accurate, flexible, and fast code.\u0000GLoW efficiently computes the frequency-dependent amplification factor for\u0000generic lens models and arbitrary impact parameters in O(1 ms) to O(10 ms)\u0000depending on the lens configuration and complexity. GLoW is readily applicable\u0000to model lensing diffraction on gravitational-wave signals, offering new means\u0000to investigate the distribution of dark-matter and large-scale structure with\u0000signals from ground and space detectors.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A solitonic model of the early universe is introduced by employing the Double-Sine-Gordon (DSG) potential. The model predicts the appropriate number of e-foldings ($N_e$) required for favored inflation and is an advantage for the model in addressing the flatness, horizon, and magnetic monopole problems. Compatibility of the model with observations, including the Planck $2018$ data cite{Akrami et al. (2020)} and the Planck $2018$ data+BK$18$+BAO cite{Ade et al. (2021)} paves the way to estimate the model's free parameters. The results generate acceptable and proper values for the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) in agreement with the Planck $2018$ data cite{Akrami et al. (2020)} and the Planck $2018$ data+BK$18$+BAO cite{Ade et al. (2021)}. Correspondingly, a consistent description of the reheating era is obtained, yielding positive reheating number of e-foldings ($N_{mathrm{reh}}$) and reheating final temperature ($T_{mathrm{reh}}$) from $10^{-2}$ GeV to $10^{16}$ GeV. Overall, the model seems viable at the inflationary and reheating eras.
通过采用双辛-戈登（Double-Sine-Gordon，DSG）势，引入了早期宇宙的索尼克模型。该模型预测了受青睐的暴胀所需的适当的电子折叠数（$N_e$），并在解决平坦性、地平线和磁单极子问题方面具有优势。该模型与观测数据，包括普朗克2018美元数据（cite{Akrami et al.(2021)} 为估计模型的自由参数铺平了道路。结果得出了光谱指数（$n_s$）和张量与尺度比（$r$）的可接受的合适值，与普朗克 2018$ 数据 （cite{Akrami et al. (2020)}）和普朗克 2018$ 数据+BK$18$+BAO （cite{Ade etal.(2021)}.相应地，得到了对再热时代的一致描述，得到了从$10^{-2}$ GeV到$10^{16}$ GeV的正再热电子折叠数（$N_{mathrm{reh}}$）和再热最终温度（$T_{mathrm{reh}}$）。总体而言，该模型在暴胀和再热时代似乎都是可行的。
{"title":"A Double-Sine-Gordon Early Universe","authors":"Behnoush Afshar, Marziyeh Peyravi, Kazuharu Bamba, Hooman Moradpour","doi":"arxiv-2409.04210","DOIUrl":"https://doi.org/arxiv-2409.04210","url":null,"abstract":"A solitonic model of the early universe is introduced by employing the\u0000Double-Sine-Gordon (DSG) potential. The model predicts the appropriate number\u0000of e-foldings ($N_e$) required for favored inflation and is an advantage for\u0000the model in addressing the flatness, horizon, and magnetic monopole problems.\u0000Compatibility of the model with observations, including the Planck $2018$ data\u0000cite{Akrami et al. (2020)} and the Planck $2018$ data+BK$18$+BAO cite{Ade et\u0000al. (2021)} paves the way to estimate the model's free parameters. The results\u0000generate acceptable and proper values for the spectral index ($n_s$) and the\u0000tensor-to-scalar ratio ($r$) in agreement with the Planck $2018$ data\u0000cite{Akrami et al. (2020)} and the Planck $2018$ data+BK$18$+BAO cite{Ade et\u0000al. (2021)}. Correspondingly, a consistent description of the reheating era is\u0000obtained, yielding positive reheating number of e-foldings ($N_{mathrm{reh}}$)\u0000and reheating final temperature ($T_{mathrm{reh}}$) from $10^{-2}$ GeV to\u0000$10^{16}$ GeV. Overall, the model seems viable at the inflationary and\u0000reheating eras.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"70 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the single-field model, the preheating process occurs through self-resonance of inflaton field. We study the nonlinear structures generated during preheating in the $alpha$-attractor models and monodromy models. The potentials have a power law form $proptoleft|phiright|^{2n}$ near the origin and a flat region away from bottom, which are consistent with current cosmological observations. The Floquet analysis shows that potential parameters in monodromy model have a significant influence on the region of resonance bands. The analytical oscillons solution for the $alpha$-attractor T model with parameter $n=1$ is derived using the small amplitude analysis method. Besides we investigate the formation of nonlinear structures, the equation of state and the energy transfer through the (3+1) dimensional lattice simulation. We find that the symmetric T potential and the asymmetric E potential in the $alpha$-attractor models have similar nonlinear dynamics. And the potential parameter $n$ in monodromy model significantly influences the lifetime of transients, whereas the parameter $q$ exerts minimal impact on the nonlinear dynamics.
{"title":"Nonlinear dynamics of oscillons and transients during preheating after single field inflation","authors":"Tianyu Jia, Yu Sang, Xue Zhang","doi":"arxiv-2409.04046","DOIUrl":"https://doi.org/arxiv-2409.04046","url":null,"abstract":"In the single-field model, the preheating process occurs through\u0000self-resonance of inflaton field. We study the nonlinear structures generated\u0000during preheating in the $alpha$-attractor models and monodromy models. The\u0000potentials have a power law form $proptoleft|phiright|^{2n}$ near the\u0000origin and a flat region away from bottom, which are consistent with current\u0000cosmological observations. The Floquet analysis shows that potential parameters\u0000in monodromy model have a significant influence on the region of resonance\u0000bands. The analytical oscillons solution for the $alpha$-attractor T model\u0000with parameter $n=1$ is derived using the small amplitude analysis method.\u0000Besides we investigate the formation of nonlinear structures, the equation of\u0000state and the energy transfer through the (3+1) dimensional lattice simulation.\u0000We find that the symmetric T potential and the asymmetric E potential in the\u0000$alpha$-attractor models have similar nonlinear dynamics. And the potential\u0000parameter $n$ in monodromy model significantly influences the lifetime of\u0000transients, whereas the parameter $q$ exerts minimal impact on the nonlinear\u0000dynamics.","PeriodicalId":501041,"journal":{"name":"arXiv - PHYS - General Relativity and Quantum Cosmology","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142199084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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