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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
mocanu
Parameter Space
alpha[0,1] (real)

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.

alpha=0.25
alpha=0.25 alpha=1.0
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 (30)

Property Kind Params Holds Value / r Status Confidence
K membership {"alpha": 0.25} -8.1287 unscreened -
K membership {"alpha": 0.5} -1.2411 unscreened -
K membership {"alpha": 0.75} 0.0364 unscreened -
r* radius {"alpha": 0.25} - r ≤ 0.920 unscreened -
r* radius {"alpha": 0.5} - r ≤ 0.920 unscreened -
r* radius {"alpha": 0.75} - r ≤ 0.920 unscreened -
S* membership {"alpha": 0.35} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.4} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.45} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.55} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.6} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.65} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.7} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.8} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.85} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.9} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.95} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 1.0} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.1} r ≤ 0.800 ✗ disproven proven
S* membership {"alpha": 0.15} r ≤ 0.800 ✗ disproven proven
S* membership {"alpha": 0.2} r ≤ 0.800 ✗ disproven proven
S* membership {"alpha": 0.3} r ≤ 0.950 ✗ disproven proven
S* membership {"alpha": 0.0} r ≤ 0.600 ✗ disproven proven
S* membership {"alpha": 0.05} r ≤ 0.800 ✗ disproven proven
S* membership {"alpha": 0.25} r ≤ 0.900 ✗ disproven proven
S* membership {"alpha": 0.5} r ≤ 0.999 ✓ proven rigorous_verified
S* membership {"alpha": 0.75} r ≤ 0.999 ✓ proven rigorous_verified
S membership {"alpha": 0.25} - unscreened -
S membership {"alpha": 0.5} - unscreened -
S membership {"alpha": 0.75} - unscreened -

Transitively Implied Properties

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

S C

Verification Runs (49)

Verifier Property Direction Outcome Domain r Witness Engine
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.800 0.9*exp(i*2.368466) boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.800 0.9*exp(i*2.396078) boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.950 0.99*exp(i*3.884039) boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.900 0.95*exp(i*2.399146) boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike proves pass 0.999 - boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.600 0.8*exp(i*2.374602) boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.800 0.9*exp(i*3.951535) boundary_v3.1
boundary_scan_centered_v31 starlike disproves pass 0.800 0.9*exp(i*3.951535) boundary_v3.1
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7121464023352646, -0.6877117867544074] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7121464023352646, -0.6877117867544074] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7121464023352646, -0.6877117867544074] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7121464023352646, -0.6877117867544074] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7121464023352646, -0.6877117867544074] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7357133772226201, 0.6624393002952698] gft-0.1.0-reaudit-20260610
pointwise_starlike_iv starlike disproves pass 0.990 [-0.7357133772226203, -0.6624393002952697] gft-0.1.0-reaudit-20260610
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.800 0.9*exp(i*2.368466) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.800 0.9*exp(i*2.386874) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.800 0.9*exp(i*2.40068) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.950 0.99*exp(i*2.40835) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.600 0.8*exp(i*2.374602) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.800 0.9*exp(i*2.380738) boundary_v3.0
boundary_scan_polynomial starlike disproves pass 0.900 0.95*exp(i*2.402214) boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0
boundary_scan_polynomial starlike proves pass 0.999 - boundary_v3.0

Parameter Sweep (49 verified instances, starlikeness × disk radius vs parameter)

Proven on full disk (r ≥ 0.999)   ·   Proven on partial disk   ·   Disproven (witness)

Instances (21)

{"alpha": 0.25} {"alpha": 0.5} {"alpha": 0.75} {"alpha": 0.0} {"alpha": 0.05} {"alpha": 0.1} {"alpha": 0.15} {"alpha": 0.2} {"alpha": 0.3} {"alpha": 0.35} {"alpha": 0.4} {"alpha": 0.45} {"alpha": 0.55} {"alpha": 0.6} {"alpha": 0.65} {"alpha": 0.7} {"alpha": 0.8} {"alpha": 0.85} {"alpha": 0.9} {"alpha": 0.95} {"alpha": 1.0}

Cited in Papers (9)

Asha Sebastian, V. Ravichandran · 2024 · J. Analysis 32(4), 1973-1990
S. Sivaprasad Kumar, Pooja Yadav · 2024
Meghna Sharma, Naveen Kumar Jain, Sushil Kumar · 2023
Sarita Agrawal, Swadesh K. Sahoo · 2014
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