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This function is certified starlike - the sharp, proven-exact coefficient bounds for the starlike class apply to it. See the certified proofs →
Canonical Key
ma_minda_cardioid

Image domain \(f(\mathbb{D})\)

The image of the unit disk under \(f\): concentric circles \(|z|=r\) and radial spokes mapped through \(f(z)=z+a_2z^2+\dots\); the bold curve is the boundary \(f(e^{i\theta})\). Rendered in your browser from the certified Taylor coefficients - nothing is computed server-side.

Taylor series
r* ≈ 0.999
Radius of starlikeness r* ≈ 0.9990
proven f is starlike on |z| < r*; the colored disk shows the certified region.

Unit disk explorer - hover to evaluate

Hover over the disk

Related

Facts (4)

Property Kind Params Holds Value / r Status Confidence
K membership {} 0.0653 🔬 screened numerical_strong
r* radius {} - r ≤ 0.700 🔬 screened numerical_strong
S* membership {} r ≤ 0.999 ✓ proven rigorous_verified
S membership {} - unscreened -

Transitively Implied Properties

Because starlikeness is proven, these properties follow by classical implications (unconditional edges in the lattice):

S C

Verification Runs (2)

Verifier Property Direction Outcome Domain r Witness Engine
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0

Instances (1)

{}

Papers in this φ-class (15)

Papers that explicitly study S*(φ) for this φ - conservatively tagged from the corpus (explicit φ formula, class symbol, or unambiguous name). Quote = the supporting passage.

Mohsan Raza, Amina Riaz, and Paweł Zaprawa · 2025
“Theorem 1. Let f ∈S∗ car be given by (1.1).”
Amina Riaz, Mohsan Raza · 2022
“Let f ∈S∗ car and be given by (1.1). Then |H2 (2) (f)| ≤4 9.”
Priyanka Goel, S. Sivaprasad Kumar · 2022
“the classes S∗ RL, S∗ C and S∗ R”
Somya Malik, V. Ravichandran · 2022
“radius of starlikeness associated with a cardioid for the function F”
Asha Sebastian, V. Ravichandran · 2021 · Mathematica Slovaca 71(1), 83-104
“S*_c = S*(1 + (4/3)z + (2/3)z^2) (cardioid)”
Shalu Yadav, Kanika Sharma, V. Ravichandran · 2021
“the class S∗ c . (i) RS∗c (T1) = 1/4 = 0.25”
Rosihan M. Ali, Kanika Sharma, V. Ravichandran · 2021
“S∗ C := S∗(ϕCAR), where ϕCAR(z) = 1 + 4z/3 + 2z2/3”
Vasudevarao Allu, Himadri Halder · 2020
“For φ(z) = 1 + 4z/3 + 2z2/3, S∗(φ) reduces to S∗ C.”
Prachi Gupta, Sumit Nagpal, V. Ravichandran · 2020
“Lemma 2.3. Let f ∈S∗ car and g ∈K. Then the function (f ∗g)(ρz)/ρ ∈S∗ car”
Kamaljeet Gangania, S. Sivaprasad Kumar · 2020
“for ψ(z) = 1 + zez, z + √ 1 + z2, eez−1 and 1 + 4z/3 + 2z2/3”
Somya Malik, V. Ravichandran · 2020
“Theorem 2.2. The S∗ c -radius RS∗c ≈0.524423.”
Kanika Khatter, See Keong Lee, V. Ravichandran · 2020
“Ωc is the region bounded by the cardioid {x + iy : (9x2 + 9y2 −18x + 5)2”
Adam Lecko, V. Ravichandran, Asha Sebastian · 2020
“S*_c = S*(1 + (4/3)z + (2/3)z^2) (cardioid)”
Kanika Sharma, Nak Eun Cho, V. Ravichandran · 2020
“ϕCAR(z) := 1 + 4z 3 + 2z2 3 ≺1 + β”
Nisha Bohra, Sushil Kumar, V. Ravichandran · 2019
“then p(z) ≺φc(z) = 1 + 4z/3 + 2z2/3. Estimates on β are sharp.”
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