<p>We study Perelman’s <InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\mathcal {W}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">W</mi> </math></EquationSource> </InlineEquation>-entropy functional on finite-dimensional <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\textrm{RCD}\)</EquationSource> <EquationSource Format="MATHML"><math> <mtext>RCD</mtext> </math></EquationSource> </InlineEquation> spaces, a synthetic generalization of spaces with Bakry–Émery Ricci curvature bounded from below. We rigorously justify the formula for the time derivative of the <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\mathcal {W}\)</EquationSource> <EquationSource Format="MATHML"><math> <mi mathvariant="script">W</mi> </math></EquationSource> </InlineEquation>-entropy and derive its monotonicity and rigidity properties. Additionally, we establish bounds for solutions of the heat equation, which are of independent interest.</p>
Perelman’s entropy and heat kernel bounds on RCD spaces
We study Perelman’s \(\mathcal {W}\)-entropy functional on finite-dimensional \(\textrm{RCD}\) spaces, a synthetic generalization of spaces with Bakry–Émery Ricci curvature bounded from below. We rigorously justify the formula for the time derivative of the \(\mathcal {W}\)-entropy and derive its monotonicity and rigidity properties. Additionally, we establish bounds for solutions of the heat equation, which are of independent interest.