{"title":"模拟-f(Q)引力:宇宙重建与能量条件","authors":"","doi":"10.1016/j.nuclphysb.2024.116677","DOIUrl":null,"url":null,"abstract":"<div><p>In this study, we present a approach to mimetic gravity incorporating a non-zero nonmetricity tensor with vanishing torsion and curvature, establishing a generalized mimetic-<span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity framework. Using the Lagrange multiplier method, we have obtained and discussed characteristics of the theory's field equations. In order to study cosmic evolution given by the hybrid scale factor, we implemented the reconstruction method in two different ways. In the first case, we have obtained corresponding Lagrange multiplier <em>η</em> and potential <em>U</em> for the specific <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>Q</mi><mo>−</mo><mn>6</mn><mi>λ</mi><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mo>(</mo><mfrac><mrow><mi>Q</mi></mrow><mrow><mn>6</mn><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>)</mo></mrow><mrow><mi>α</mi></mrow></msup></math></span> function, while in the second scenario we have recovered <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> functional and mimetic potential for the given Lagrange multiplier <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>+</mo><mi>γ</mi><msup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>. Subsequently, we explore the fundamental properties of the <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>Q</mi><mo>−</mo><mn>6</mn><mi>λ</mi><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mo>(</mo><mfrac><mrow><mi>Q</mi></mrow><mrow><mn>6</mn><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>)</mo></mrow><mrow><mi>α</mi></mrow></msup></math></span> model and analyse the energy conditions to establish its validity. Our findings indicate that the introduced framework allows for the derivation of cosmological models that satisfy necessary energy constraints. Specifically, we show that the considered model enters the quintessence region for the equation of state parameter <em>w</em>, simultaneously violating the strong energy condition (SEC), leading to repulsive behaviour consistent with accelerated expansion. Thus, the introduced extension demonstrates potential for accurately describing cosmological models.</p></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0550321324002438/pdfft?md5=bbac7e76e2bd3f053445cdca0bcabc18&pid=1-s2.0-S0550321324002438-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Mimetic-f(Q) gravity: Cosmic reconstruction and energy conditions\",\"authors\":\"\",\"doi\":\"10.1016/j.nuclphysb.2024.116677\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this study, we present a approach to mimetic gravity incorporating a non-zero nonmetricity tensor with vanishing torsion and curvature, establishing a generalized mimetic-<span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity framework. Using the Lagrange multiplier method, we have obtained and discussed characteristics of the theory's field equations. In order to study cosmic evolution given by the hybrid scale factor, we implemented the reconstruction method in two different ways. In the first case, we have obtained corresponding Lagrange multiplier <em>η</em> and potential <em>U</em> for the specific <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>Q</mi><mo>−</mo><mn>6</mn><mi>λ</mi><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mo>(</mo><mfrac><mrow><mi>Q</mi></mrow><mrow><mn>6</mn><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>)</mo></mrow><mrow><mi>α</mi></mrow></msup></math></span> function, while in the second scenario we have recovered <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> functional and mimetic potential for the given Lagrange multiplier <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>+</mo><mi>γ</mi><msup><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span>. Subsequently, we explore the fundamental properties of the <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo><mo>=</mo><mi>Q</mi><mo>−</mo><mn>6</mn><mi>λ</mi><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup><msup><mrow><mo>(</mo><mfrac><mrow><mi>Q</mi></mrow><mrow><mn>6</mn><msup><mrow><mi>M</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></mfrac><mo>)</mo></mrow><mrow><mi>α</mi></mrow></msup></math></span> model and analyse the energy conditions to establish its validity. Our findings indicate that the introduced framework allows for the derivation of cosmological models that satisfy necessary energy constraints. Specifically, we show that the considered model enters the quintessence region for the equation of state parameter <em>w</em>, simultaneously violating the strong energy condition (SEC), leading to repulsive behaviour consistent with accelerated expansion. Thus, the introduced extension demonstrates potential for accurately describing cosmological models.</p></div>\",\"PeriodicalId\":54712,\"journal\":{\"name\":\"Nuclear Physics B\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-09-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0550321324002438/pdfft?md5=bbac7e76e2bd3f053445cdca0bcabc18&pid=1-s2.0-S0550321324002438-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nuclear Physics B\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0550321324002438\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, PARTICLES & FIELDS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Physics B","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0550321324002438","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
Mimetic-f(Q) gravity: Cosmic reconstruction and energy conditions
In this study, we present a approach to mimetic gravity incorporating a non-zero nonmetricity tensor with vanishing torsion and curvature, establishing a generalized mimetic- gravity framework. Using the Lagrange multiplier method, we have obtained and discussed characteristics of the theory's field equations. In order to study cosmic evolution given by the hybrid scale factor, we implemented the reconstruction method in two different ways. In the first case, we have obtained corresponding Lagrange multiplier η and potential U for the specific function, while in the second scenario we have recovered functional and mimetic potential for the given Lagrange multiplier . Subsequently, we explore the fundamental properties of the model and analyse the energy conditions to establish its validity. Our findings indicate that the introduced framework allows for the derivation of cosmological models that satisfy necessary energy constraints. Specifically, we show that the considered model enters the quintessence region for the equation of state parameter w, simultaneously violating the strong energy condition (SEC), leading to repulsive behaviour consistent with accelerated expansion. Thus, the introduced extension demonstrates potential for accurately describing cosmological models.
期刊介绍:
Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics - phenomenology, high energy physics - theory, high energy physics - experiment, and quantum field theory, statistical systems, and mathematical physics. The emphasis is on original research papers (Frontiers Articles or Full Length Articles), but Review Articles are also welcome.