Saeed Noori Gashti, Mohammad Reza Alipour, Mohammad Ali S. Afshar
In recent years, inflationary models have been studied from different perspectives using different conditions. Now, in this paper, we want to investigate the inverse monomial Inflation $(IMI)$ on the brane. We limit our results to the potentials of the form $frac{M^{4+sigma}}{phi^{sigma}}$. We calculate some cosmological parameters and then we investigate the satisfaction of the model with some conjectures of the swampland program. We will check the model's compatibility with the refined dS swampland conjecture(RDSSC), further refining the de Sitter swampland conjecture (FRSDC), scalar weak gravity (SWGC), and strong scalar weak gravity conjecture (SSWGC). Despite the incompatibility with (DSSC), We find a specific region of compatibility with other ones which means it satisfied the (FRDSSC) for example with (a=0.982873, b=0.017127, q=2.2). Also, the model is compatible with the (SWGC) with the ($phileq sigma+2$) condition and consistent with the (SSWGC) with the ($phi leq sqrt{(sigma+2)(sigma+1)}$) condition. Since inverse monomial Inflation(IMI) on the brane could satisfy some swampland conjecture simultaneously, it has the potential to be a "real" inflation model of the universe.
{"title":"Exploring the Parameter Space of Inflation Model on the Brane and its Compatibility with the Swampland Conjectures","authors":"Saeed Noori Gashti, Mohammad Reza Alipour, Mohammad Ali S. Afshar","doi":"arxiv-2409.06488","DOIUrl":"https://doi.org/arxiv-2409.06488","url":null,"abstract":"In recent years, inflationary models have been studied from different\u0000perspectives using different conditions. Now, in this paper, we want to\u0000investigate the inverse monomial Inflation $(IMI)$ on the brane. We limit our\u0000results to the potentials of the form $frac{M^{4+sigma}}{phi^{sigma}}$. We\u0000calculate some cosmological parameters and then we investigate the satisfaction\u0000of the model with some conjectures of the swampland program. We will check the\u0000model's compatibility with the refined dS swampland conjecture(RDSSC), further\u0000refining the de Sitter swampland conjecture (FRSDC), scalar weak gravity\u0000(SWGC), and strong scalar weak gravity conjecture (SSWGC). Despite the\u0000incompatibility with (DSSC), We find a specific region of compatibility with\u0000other ones which means it satisfied the (FRDSSC) for example with (a=0.982873,\u0000b=0.017127, q=2.2). Also, the model is compatible with the (SWGC) with the\u0000($phileq sigma+2$) condition and consistent with the (SSWGC) with the ($phi\u0000leq sqrt{(sigma+2)(sigma+1)}$) condition. Since inverse monomial\u0000Inflation(IMI) on the brane could satisfy some swampland conjecture\u0000simultaneously, it has the potential to be a \"real\" inflation model of the\u0000universe.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"384 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176037","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 consider spinors on the total space of a Kaluza-Klein model with fuzzy sphere fibre and geometrically realised Dirac operator on the product. We show that a single massless spinor on the product appears on spacetime as multiplets of spinors with a particular signature of differing masses and $SU(2)$ Yang-Mills charges. For example, for the reduced fuzzy sphere isomorphic to $M_2(mathbb{C})$, a massless spinor appears as two $SU(2)$ doublets and an $SU(2)$ quadruplet in mass ratios $1:5/3:7/3$. Although such signatures do not appear to exactly math the Standard Model, the paper provides proof of concept of the approach, which can be applied to other noncommutative fibre algebras.
{"title":"Fermions in the fuzzy sphere Kaluza-Klein model","authors":"Chengcheng Liu, Shahn Majid","doi":"arxiv-2409.06668","DOIUrl":"https://doi.org/arxiv-2409.06668","url":null,"abstract":"We consider spinors on the total space of a Kaluza-Klein model with fuzzy\u0000sphere fibre and geometrically realised Dirac operator on the product. We show\u0000that a single massless spinor on the product appears on spacetime as multiplets\u0000of spinors with a particular signature of differing masses and $SU(2)$\u0000Yang-Mills charges. For example, for the reduced fuzzy sphere isomorphic to\u0000$M_2(mathbb{C})$, a massless spinor appears as two $SU(2)$ doublets and an\u0000$SU(2)$ quadruplet in mass ratios $1:5/3:7/3$. Although such signatures do not\u0000appear to exactly math the Standard Model, the paper provides proof of concept\u0000of the approach, which can be applied to other noncommutative fibre algebras.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176028","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 this thesis we study the framework of asymptotic Hodge theory and its applications in both the string landscape and the landscape of 2d integrable field theories. We show how this mathematical framework allows for a general characterization of the asymptotic behaviour of physical couplings in low-energy effective theories coming from string theory, and apply this knowledge to investigate the finiteness and geometric structure of the string landscape landscape. At the same time, we find that the defining equations of variations of Hodge structure also arise in the context of certain integrable field theories, which opens the way to finding new classes of very general solutions to said models. Part I reviews the relevant aspects of type IIB / F-theory flux compactifications and the resulting landscape of 4d low-energy effective $mathcal{N}=1$ supergravity theories. Part II provides an in-depth discussion on asymptotic Hodge theory, including detailed explanations on the nilpotent orbit theorem of Schmid, and the multi-variable Sl(2)-orbit theorem of Cattani, Kaplan, and Schmid. This part of the thesis also contains new results regarding the multi-variable bulk reconstruction procedure, which have not appeared in the author's previous publications. Part III concerns the application of the aforementioned results to study the finiteness of the F-theory flux landscape. Additionally, motivated by recent advances in the field of o-minimal geometry and the theory of unlikely intersections, we propose three conjectures which aim to address finer features of the flux landscape. Part IV investigates two corners of the landscape of 2d integrable non-linear sigma-models, namely the $lambda$-deformed gauged WZW model and the critical bi-Yang-Baxter model. Notably, it is shown that asymptotic Hodge theory can be used to find broad classes of solutions these models.
在这篇论文中，我们研究了渐近霍奇理论的框架及其在弦景观和二维可积场理论景观中的应用。我们展示了这一数学框架如何允许对来自弦理论的低能有效理论中物理耦合的渐近行为进行一般描述，并将这一知识应用于研究弦景观的有限性和几何结构。同时，我们发现霍奇结构变量的定义方程也出现在某些可积场理论中，这就为找到上述模型的新一类非常一般的解开辟了道路。第一部分回顾了IIB型/F理论通约化的相关方面，以及由此产生的4d低能有效$mathcal{N}=1$超引力理论的面貌。第二部分深入讨论了渐近霍奇理论，包括详细解释了施密德的零potent轨道定理，以及卡塔尼、卡普兰和施密德的多变量Sl(2)轨道定理。论文的这一部分还包含了有关多变量批量重构过程的新结果，这些结果在作者以前的出版物中没有出现过。第三部分涉及应用上述结果研究 F 理论通量景观的有限性。此外，受 O 最小几何和不可能交集理论领域最新进展的启发，我们提出了三个猜想，旨在解决通量景观的更精细特征问题。第四部分研究了二维可积分非线性σ模型景观的两个角落，即$lambda$变形的 gauged WZW 模型和临界比-杨-巴克斯特模型。值得注意的是，研究表明可以利用渐近霍奇理论找到这些模型的广泛解类。
{"title":"Asymptotic Hodge Theory in String Compactifications and Integrable Systems","authors":"Jeroen Monnee","doi":"arxiv-2409.06794","DOIUrl":"https://doi.org/arxiv-2409.06794","url":null,"abstract":"In this thesis we study the framework of asymptotic Hodge theory and its\u0000applications in both the string landscape and the landscape of 2d integrable\u0000field theories. We show how this mathematical framework allows for a general\u0000characterization of the asymptotic behaviour of physical couplings in\u0000low-energy effective theories coming from string theory, and apply this\u0000knowledge to investigate the finiteness and geometric structure of the string\u0000landscape landscape. At the same time, we find that the defining equations of\u0000variations of Hodge structure also arise in the context of certain integrable\u0000field theories, which opens the way to finding new classes of very general\u0000solutions to said models. Part I reviews the relevant aspects of type IIB / F-theory flux\u0000compactifications and the resulting landscape of 4d low-energy effective\u0000$mathcal{N}=1$ supergravity theories. Part II provides an in-depth discussion on asymptotic Hodge theory, including\u0000detailed explanations on the nilpotent orbit theorem of Schmid, and the\u0000multi-variable Sl(2)-orbit theorem of Cattani, Kaplan, and Schmid. This part of\u0000the thesis also contains new results regarding the multi-variable bulk\u0000reconstruction procedure, which have not appeared in the author's previous\u0000publications. Part III concerns the application of the aforementioned results to study the\u0000finiteness of the F-theory flux landscape. Additionally, motivated by recent\u0000advances in the field of o-minimal geometry and the theory of unlikely\u0000intersections, we propose three conjectures which aim to address finer features\u0000of the flux landscape. Part IV investigates two corners of the landscape of 2d integrable non-linear\u0000sigma-models, namely the $lambda$-deformed gauged WZW model and the critical\u0000bi-Yang-Baxter model. Notably, it is shown that asymptotic Hodge theory can be\u0000used to find broad classes of solutions these models.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176019","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}
Maxime De Sousa, Aurélien Barrau, Killian Martineau
The issue of consistency is crucial in quantum gravity. It has recently been intensively addressed for effective symmetry-reduced models. In this article, we exhaustively study the anomaly freedom of effective loop quantum cosmology with generalized holonomy corrections, considering loop correction of the constraints at the perturbative order. We pedagogically explain why, although the holonomy correction -- including the details of the chosen scheme -- applied on the background part of the constraints is crucial, it becomes irrelevant when implemented on perturbative expansions, in the sense that all consequences are "absorbed" in the counter-terms used for the regularization. The possibility of closing the algebra of constraints without counter-terms is also studied. It is argued that, although enforcing a first-class algebra is a strong requirement, this can be achieved in several different ways, often overlooked, which generates ambiguities on the restriction of the form of the generalized holonomy correction. Those ambiguities are examined in details, leading to the conclusion that the consistency of the effective theory for cosmological perturbations, especially when considering scalar modes, cannot be achieved without counter-terms. We also take the opportunity of this work to clarify, as much as possible, all the required steps so that future works have a clear material at disposal. In particular, a highly detailed calculation of all the brackets is provided, emphasizing the (usually implicit) assumptions, hypotheses and manipulations required to ensure the closure of the algebra. Prospects for future works are underlined.
{"title":"Anomaly freedom in effective Loop Quantum Cosmology: pedagogical summary and generalized holonomy corrections","authors":"Maxime De Sousa, Aurélien Barrau, Killian Martineau","doi":"arxiv-2409.06441","DOIUrl":"https://doi.org/arxiv-2409.06441","url":null,"abstract":"The issue of consistency is crucial in quantum gravity. It has recently been\u0000intensively addressed for effective symmetry-reduced models. In this article,\u0000we exhaustively study the anomaly freedom of effective loop quantum cosmology\u0000with generalized holonomy corrections, considering loop correction of the\u0000constraints at the perturbative order. We pedagogically explain why, although\u0000the holonomy correction -- including the details of the chosen scheme --\u0000applied on the background part of the constraints is crucial, it becomes\u0000irrelevant when implemented on perturbative expansions, in the sense that all\u0000consequences are \"absorbed\" in the counter-terms used for the regularization.\u0000The possibility of closing the algebra of constraints without counter-terms is\u0000also studied. It is argued that, although enforcing a first-class algebra is a\u0000strong requirement, this can be achieved in several different ways, often\u0000overlooked, which generates ambiguities on the restriction of the form of the\u0000generalized holonomy correction. Those ambiguities are examined in details,\u0000leading to the conclusion that the consistency of the effective theory for\u0000cosmological perturbations, especially when considering scalar modes, cannot be\u0000achieved without counter-terms. We also take the opportunity of this work to\u0000clarify, as much as possible, all the required steps so that future works have\u0000a clear material at disposal. In particular, a highly detailed calculation of\u0000all the brackets is provided, emphasizing the (usually implicit) assumptions,\u0000hypotheses and manipulations required to ensure the closure of the algebra.\u0000Prospects for future works are underlined.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"122 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176064","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}
There exist two consistent theories of self-interacting gravitons: general relativity and Weyl transverse gravity. The latter has the same classical solutions as general relativity, but different local symmetries. We argue that Weyl transverse gravity also naturally arises from thermodynamic arguments. In particular, we show that thermodynamic equilibrium of local causal diamonds together with the strong equivalence principle encodes the gravitational dynamics of Weyl transverse gravity rather than general relativity. We obtain this result in a self-consistent way, verifying the validity of our initial assumptions, i.e. the proportionality between entropy and area and the different versions of the equivalence principle in Weyl transverse gravity. Furthermore, we extend the thermodynamic derivation of the equations of motion from Weyl transverse gravity to a class of modified theories of gravity with the same local symmetries. For this purpose, we employ the general expression for Wald entropy in such theories.
{"title":"From spacetime thermodynamics to Weyl transverse gravity","authors":"Ana Alonso-Serrano, Luis J. Garay, Marek Liška","doi":"arxiv-2409.06645","DOIUrl":"https://doi.org/arxiv-2409.06645","url":null,"abstract":"There exist two consistent theories of self-interacting gravitons: general\u0000relativity and Weyl transverse gravity. The latter has the same classical\u0000solutions as general relativity, but different local symmetries. We argue that\u0000Weyl transverse gravity also naturally arises from thermodynamic arguments. In\u0000particular, we show that thermodynamic equilibrium of local causal diamonds\u0000together with the strong equivalence principle encodes the gravitational\u0000dynamics of Weyl transverse gravity rather than general relativity. We obtain\u0000this result in a self-consistent way, verifying the validity of our initial\u0000assumptions, i.e. the proportionality between entropy and area and the\u0000different versions of the equivalence principle in Weyl transverse gravity.\u0000Furthermore, we extend the thermodynamic derivation of the equations of motion\u0000from Weyl transverse gravity to a class of modified theories of gravity with\u0000the same local symmetries. For this purpose, we employ the general expression\u0000for Wald entropy in such theories.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176035","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}
Kazunori Kohri, Takahiro Terada, Tsutomu T. Yanagida
Quantum evaporation of a black hole is conventionally studied semiclassically by assuming self-similarity of the black hole throughout the evaporation process. However, its validity was recently questioned, and the lifetime of a black hole is conjectured to be much extended by the memory burden effect. It gives rise to the possibility that the primordial black holes (PBHs) lighter than $10^{10}$ grams are the dark matter in the Universe. To probe such PBH dark matter, we study gravitational waves (GWs) induced by primordial curvature perturbations that produced the PBHs. We find $Omega_text{GW}(f_text{peak})h^2 = 7 times 10^{-9}$ with the peak frequency $f_text{peak} = 1times 10^{3} , (M_text{PBH}/(10^{10},mathrm{g}))^{-1/2}, mathrm{Hz}$, and the induced GWs associated with the PBH dark matter whose initial mass is greater than about $10^7$ grams can be tested by future observations such as Cosmic Explorer. Furthermore, the scenario can be in principle confirmed by detecting another GW signal from the mergers of PBHs, which leads to high-frequency GWs with $f_text{peak} = 2 times 10^{27}, (M_text{PBH, ini}/(10^{10}, mathrm{g}))^{-1} , mathrm{Hz} $. On the other hand, the induced GW signals stronger than expected would contradict the dark matter abundance and exclude the memory burden effect.
{"title":"Induced Gravitational Waves probing Primordial Black Hole Dark Matter with Memory Burden","authors":"Kazunori Kohri, Takahiro Terada, Tsutomu T. Yanagida","doi":"arxiv-2409.06365","DOIUrl":"https://doi.org/arxiv-2409.06365","url":null,"abstract":"Quantum evaporation of a black hole is conventionally studied semiclassically\u0000by assuming self-similarity of the black hole throughout the evaporation\u0000process. However, its validity was recently questioned, and the lifetime of a\u0000black hole is conjectured to be much extended by the memory burden effect. It\u0000gives rise to the possibility that the primordial black holes (PBHs) lighter\u0000than $10^{10}$ grams are the dark matter in the Universe. To probe such PBH\u0000dark matter, we study gravitational waves (GWs) induced by primordial curvature\u0000perturbations that produced the PBHs. We find\u0000$Omega_text{GW}(f_text{peak})h^2 = 7 times 10^{-9}$ with the peak frequency\u0000$f_text{peak} = 1times 10^{3} ,\u0000(M_text{PBH}/(10^{10},mathrm{g}))^{-1/2}, mathrm{Hz}$, and the induced GWs\u0000associated with the PBH dark matter whose initial mass is greater than about\u0000$10^7$ grams can be tested by future observations such as Cosmic Explorer.\u0000Furthermore, the scenario can be in principle confirmed by detecting another GW\u0000signal from the mergers of PBHs, which leads to high-frequency GWs with\u0000$f_text{peak} = 2 times 10^{27}, (M_text{PBH, ini}/(10^{10},\u0000mathrm{g}))^{-1} , mathrm{Hz} $. On the other hand, the induced GW signals\u0000stronger than expected would contradict the dark matter abundance and exclude\u0000the memory burden effect.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176071","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 reconstruction of an inflationary universe considering the parametrization of the scalar spectral index as a function of the number of $e-$folds in the framework of a modified Friedmann equation is analyzed. In this context, we examine the possibility of reconstructing the Hubble parameter together with the effective potential considering a modified Friedmann equation specified by $mathcal{F}(H)propto rho$, where $mathcal{F}(H)$ corresponds to an arbitrary function of the Hubble parameter $H$ and $rho$ denotes the energy density associated with the matter in the universe. To reconstruct the background variables during the inflationary scenario, we develop a new methodology by expressing the spectral index in terms of the Hubble parameter and its derivatives. Thus, we obtain a general formalism for the reconstruction of the inflation, using the slow roll approximation together with the parametrization of the scalar spectral index as a function of the number of $e-$folds $N$. As specific examples, we consider the simplest attractor $n_s-1=-2/N$ together with different functions $mathcal{F}(H)$, associated to the modified Friedmann equation, to rebuild the Hubble parameter and the effective potential in terms of the scalar field $phi$. Additionally, we examine the reheating epoch by considering a constant equation of state parameter, in which we determine the temperature and the number of e-folds during this epoch, using the background variables found during the reconstruction of the different $mathcal{F}(H)-$models studied. Besides, we constrain the different parameters associated with the reconstructed inflationary $mathcal{F}(H)-$models during the epochs of inflation and reheating, using current astronomical data from Planck and BICEP/Keck results.
{"title":"Reconstructing inflation and reheating in the framework of a generalized $mathcal{F}(H)$ Friedmann equation","authors":"Ramon Herrera, Carlos Rios","doi":"arxiv-2409.06844","DOIUrl":"https://doi.org/arxiv-2409.06844","url":null,"abstract":"The reconstruction of an inflationary universe considering the\u0000parametrization of the scalar spectral index as a function of the number of\u0000$e-$folds in the framework of a modified Friedmann equation is analyzed. In\u0000this context, we examine the possibility of reconstructing the Hubble parameter\u0000together with the effective potential considering a modified Friedmann equation\u0000specified by $mathcal{F}(H)propto rho$, where $mathcal{F}(H)$ corresponds\u0000to an arbitrary function of the Hubble parameter $H$ and $rho$ denotes the\u0000energy density associated with the matter in the universe. To reconstruct the\u0000background variables during the inflationary scenario, we develop a new\u0000methodology by expressing the spectral index in terms of the Hubble parameter\u0000and its derivatives. Thus, we obtain a general formalism for the reconstruction\u0000of the inflation, using the slow roll approximation together with the\u0000parametrization of the scalar spectral index as a function of the number of\u0000$e-$folds $N$. As specific examples, we consider the simplest attractor\u0000$n_s-1=-2/N$ together with different functions $mathcal{F}(H)$, associated to\u0000the modified Friedmann equation, to rebuild the Hubble parameter and the\u0000effective potential in terms of the scalar field $phi$. Additionally, we\u0000examine the reheating epoch by considering a constant equation of state\u0000parameter, in which we determine the temperature and the number of e-folds\u0000during this epoch, using the background variables found during the\u0000reconstruction of the different $mathcal{F}(H)-$models studied. Besides, we\u0000constrain the different parameters associated with the reconstructed\u0000inflationary $mathcal{F}(H)-$models during the epochs of inflation and\u0000reheating, using current astronomical data from Planck and BICEP/Keck results.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176025","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 two-dimensional flat space, the oscillatory motion of a closed folded string--or alternatively, two massless particles connected by a string--can be quantized using the 't Hooft equation. This paper presents an alternative method for quantizing the folded string in anti-de Sitter space. By using variables inspired by integrability, setting $g equiv {(R_text{AdS})^2 over 2pi alpha'}$ to a specific p-dependent $mathcal{O}(1)$ value, and applying a particular boundary condition to the antisymmetrized wavefunction, we obtain a spectrum that precisely matches that of fermion bilinear operators in the disorder-averaged Sachdev-Ye-Kitaev model with p-fermion interactions.
{"title":"Quantizing the folded string in AdS$_2$","authors":"David Vegh","doi":"arxiv-2409.06663","DOIUrl":"https://doi.org/arxiv-2409.06663","url":null,"abstract":"In two-dimensional flat space, the oscillatory motion of a closed folded\u0000string--or alternatively, two massless particles connected by a string--can be\u0000quantized using the 't Hooft equation. This paper presents an alternative\u0000method for quantizing the folded string in anti-de Sitter space. By using\u0000variables inspired by integrability, setting $g equiv {(R_text{AdS})^2 over\u00002pi alpha'}$ to a specific p-dependent $mathcal{O}(1)$ value, and applying a\u0000particular boundary condition to the antisymmetrized wavefunction, we obtain a\u0000spectrum that precisely matches that of fermion bilinear operators in the\u0000disorder-averaged Sachdev-Ye-Kitaev model with p-fermion interactions.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176030","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 general covariant Einstein-Gauss-Bonnet Gravity in Four-Dimensional (4D EGB) spacetime is shown to bypass Lovelock's theorem and is free from Ostrogradsky instability. Meanwhile, the bumblebee theory is a vector-tensor theory. It extends the Einstein--Maxwell theory that allows for the spontaneous symmetry breaking that leads to the field acquiring a vacuum expectation value, introducing Lorentz violation into the system. We investigate rotating black holes in the 4D EGB-bumblebee gravity model where Lorentz symmetry is spontaneously broken -- Kerr EGB bumblebee (KEGBB) black holes. The latest observations from the Event Horizon Telescope (EHT) of the supermassive black holes (SMBHs) M87* and Sgr A* have sparked intensified interest in the study of black hole shadows, which present a novel avenue for investigating SMBHs within the strong-field regime. Motivated by this, we model SMBHs M87* and Sgr A* as KEGBB black holes, and using the EHT observation result, for given $l$, to find earlier upper limits on the $alpha$ and $a$ are altered. The KEGBB and Kerr black holes are indiscernible in some parameter space, and one cannot rule out the possibility that the former may serve as strong candidates for astrophysical black holes. Employing our newly developed parameter estimation technique, we use two EHT observables -- namely, the angular diameter of the shadow, $d_{sh}$, and the axial ratio, $mathcal{D}_A$ -- to estimate parameters of M87* and Sgr A* taking into account observational errors associated with the EHT results.
{"title":"Testing EGB gravity coupled to bumblebee field and black hole parameter estimation with EHT observations","authors":"Misba Afrin, Sushant G. Ghosh, Anzhong Wang","doi":"arxiv-2409.06218","DOIUrl":"https://doi.org/arxiv-2409.06218","url":null,"abstract":"A general covariant Einstein-Gauss-Bonnet Gravity in Four-Dimensional (4D\u0000EGB) spacetime is shown to bypass Lovelock's theorem and is free from\u0000Ostrogradsky instability. Meanwhile, the bumblebee theory is a vector-tensor\u0000theory. It extends the Einstein--Maxwell theory that allows for the spontaneous\u0000symmetry breaking that leads to the field acquiring a vacuum expectation value,\u0000introducing Lorentz violation into the system. We investigate rotating black\u0000holes in the 4D EGB-bumblebee gravity model where Lorentz symmetry is\u0000spontaneously broken -- Kerr EGB bumblebee (KEGBB) black holes. The latest\u0000observations from the Event Horizon Telescope (EHT) of the supermassive black\u0000holes (SMBHs) M87* and Sgr A* have sparked intensified interest in the study of\u0000black hole shadows, which present a novel avenue for investigating SMBHs within\u0000the strong-field regime. Motivated by this, we model SMBHs M87* and Sgr A* as\u0000KEGBB black holes, and using the EHT observation result, for given $l$, to find\u0000earlier upper limits on the $alpha$ and $a$ are altered. The KEGBB and Kerr\u0000black holes are indiscernible in some parameter space, and one cannot rule out\u0000the possibility that the former may serve as strong candidates for\u0000astrophysical black holes. Employing our newly developed parameter estimation\u0000technique, we use two EHT observables -- namely, the angular diameter of the\u0000shadow, $d_{sh}$, and the axial ratio, $mathcal{D}_A$ -- to estimate\u0000parameters of M87* and Sgr A* taking into account observational errors\u0000associated with the EHT results.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176067","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 propose a holographic duality for the boundary Lifshitz field theory (BLFT). Similar to holographic BCFT, holographic BLFT can be consistently defined by imposing either a Neumann boundary condition (NBC) or a conformal boundary condition (CBC) on the end of the world (EOW) brane. We propose $g$-functions and derive $g$-theorem for these two types of holographic BLFT. On the field theory side, we consider BLFT whose path integral is prescribed to include also paths bouncing off the boundary. The entanglement entropy for an interval for the Lifshitz invariant ground state is computed in the saddle point approximation, and is found to agree precisely with the holographic result in both limits when the interval is very close or very far away from the boundary.
{"title":"Holography for Boundary Lifshitz Field Theory","authors":"Chong-Sun Chu, Ignacio Garrido Gonzalez, Himanshu Parihar","doi":"arxiv-2409.06667","DOIUrl":"https://doi.org/arxiv-2409.06667","url":null,"abstract":"We propose a holographic duality for the boundary Lifshitz field theory\u0000(BLFT). Similar to holographic BCFT, holographic BLFT can be consistently\u0000defined by imposing either a Neumann boundary condition (NBC) or a conformal\u0000boundary condition (CBC) on the end of the world (EOW) brane. We propose\u0000$g$-functions and derive $g$-theorem for these two types of holographic BLFT.\u0000On the field theory side, we consider BLFT whose path integral is prescribed to\u0000include also paths bouncing off the boundary. The entanglement entropy for an\u0000interval for the Lifshitz invariant ground state is computed in the saddle\u0000point approximation, and is found to agree precisely with the holographic\u0000result in both limits when the interval is very close or very far away from the\u0000boundary.","PeriodicalId":501339,"journal":{"name":"arXiv - PHYS - High Energy Physics - Theory","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176029","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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