<p>We develop Tsallis holographic dark energy (THDE) models using the Saez-Ballester scalar-tensor theory of gravitation, taking into account both non-interacting and interacting scenarios. The interactive model has a sign-changing interaction between dark energy and dark matter, allowing energy transmission to vary as the Universe evolved. We investigate important cosmological factors such as energy densities (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$\rho _t,\rho _m$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>ρ</mi> <mi>t</mi> </msub> <mo>,</mo> <msub> <mi>ρ</mi> <mi>m</mi> </msub> </mrow> </math></EquationSource> </InlineEquation>), the equation of state parameter (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\omega _t$</EquationSource> <EquationSource Format="MATHML"><math> <msub> <mi>ω</mi> <mi>t</mi> </msub> </math></EquationSource> </InlineEquation>), the deceleration parameter (q), skewness parameter (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">$\gamma$</EquationSource> <EquationSource Format="MATHML"><math> <mi>γ</mi> </math></EquationSource> </InlineEquation>), trajectory <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$(\omega _t-\omega '_t)$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo stretchy="false">(</mo> <msub> <mi>ω</mi> <mi>t</mi> </msub> <mo>-</mo> <msubsup> <mi>ω</mi> <mi>t</mi> <mo>′</mo> </msubsup> <mo stretchy="false">)</mo> </mrow> </math></EquationSource> </InlineEquation>, square of sound speed (<InlineEquation ID="IEq5"> <EquationSource Format="TEX">$v^{2}_{s}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mi>v</mi> <mi>s</mi> <mn>2</mn> </msubsup> </math></EquationSource> </InlineEquation>) and statefinder diagnostics (r,s). Our findings show that both interacting and non-interacting Tsallis holographic dark energy models are inherently unstable, demonstrating THDE’s unique dynamical property under sign-changeable interaction in the Saez-Ballester scalar-tensor framework.</p>

Plane symmetric models with Tsallis holographic dark energy in Saez-Ballester theory

期刊论文
发表日期：

2026年3月9日

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D. Neelima,
A. Narasimharao

摘要

We develop Tsallis holographic dark energy (THDE) models using the Saez-Ballester scalar-tensor theory of gravitation, taking into account both non-interacting and interacting scenarios. The interactive model has a sign-changing interaction between dark energy and dark matter, allowing energy transmission to vary as the Universe evolved. We investigate important cosmological factors such as energy densities ( $\rho _t,\rho _m$ $ρ_{t}, ρ_{m}$ ), the equation of state parameter ( $\omega _t$ $ω_{t}$ ), the deceleration parameter (q), skewness parameter ( $\gamma$ $γ$ ), trajectory $(\omega _t-\omega '_t)$ $(ω_{t} - ω_{t}^{'})$ , square of sound speed ( $v^{2}_{s}$ $v_{s}^{2}$ ) and statefinder diagnostics (r,s). Our findings show that both interacting and non-interacting Tsallis holographic dark energy models are inherently unstable, demonstrating THDE’s unique dynamical property under sign-changeable interaction in the Saez-Ballester scalar-tensor framework.