List of symbols
\(a,b,c\) | Constants in polynomial (§F) |
\(a,b,c,d,i\) | Coefficients of power law of ABR or OAE (§11.7.3, §17.3.1) |
\(a,b,d\) | Linear canonical transform (LCT) coefficients (§C) |
\(a\) | Complex temporal envelope |
\(a\) | Arbitrary signal (§14) |
\(A\) | Complex envelope spectrum |
\(a_g \) | Ideal geometrical image of envelope (§13.2.1) |
\(a_n\) | Complex temporal envelope in neural domain (§12.2) |
\(a_s\) | Sampled signal (§14) |
\(A_s\) | Sampled spectrum (§14) |
\(b_n\) | Random eigenfunction coefficient (§8.2.6) |
\(B\) | Bandwidth |
\(B_n\) | Noise-equivalent bandwidth (§9.4) |
\(c\) | Wave speed; Speed of light; Speed of sound |
\(C\) | Circle of confusion (§4) |
\(C\) | Channel capacity (§5.2.1) |
\(C\) | Schroeder phase curvature (§12.4.1, §17.3.1) |
\(C\) | Real part of Fresnel integral (§D) |
\(C_T\) | Linear canonical transform (LCT) kernel for operator \(T\) (§C) |
\(d\) | Temporal acuity; Detectable gap (§13.4.4, §15.6, §F) |
\(d\) | Group-delay dispersion impulse response (§12, §13.2) |
\(D\) | Aperture size (§4) |
\(D\) | Group-delay dispersion transfer function (§12, §13.2) |
\(D\) | Pulse sequence duration (§E) |
\(D'\) | Pulse sequence duration minus the last pulse duration (§E) |
\(D_a\) | Acoustic dipole strength (Table §3.1) |
\(D_e\) | Electromagnetic dipole strength (Table §3.1) |
\(\boldsymbol{\mathbf{E}}\) | Electric field (vector) (Table §3.1) |
\(E\) | Electric field (scalar) (§4) |
\(ERB\) | Equivalent rectangular bandwidth of auditory filter |
\(f\) | Frequency |
\(f\) | Focal length (§4) |
\(f\) | Arbitrary function (§3.2.1) |
\(F\) | Fourier transform of arbitrary function \(f\) (§3.2.1) |
\(\boldsymbol{\mathbf{F}}\) | Arbitrary wave field (Table §3.1) |
\(f'\) | Doppler-shifted frequency (§3.3.3) |
\(f'\) | Remapped imaged frequency under binaural diplacusis (§17.3.3) |
\(f^\#\) | F-number (§4.2.1) |
\(f_0\) | Fundamental frequency |
\(f_c\) | Carrier frequency |
\(f_m\) | Modulation frequency |
\(f_n\) | Cutoff frequency (Figure §9.3) |
\(f_T\) | Focal time |
\(f_{T,gg}\) | Focal time estimate of the gerbil and guinea pig time lens |
\(f_{T,h}\) | Focal time estimate of the human time lens |
\(f_s\) | Sampling rate |
\(f_T^\#\) | Temporal imaging f-number (§15.11.1) |
\({\cal F}\) | Fourier transform |
\({\cal F}^{-1}\) | Inverse Fourier transform |
\(g\) | Arbitrary function (§3.2.1) |
\(g\) | Complex envelope / Mapping function (§5.3.1) |
\(g_1,g_2\) | Fresnel integral variables (§D) |
\(g_T\) | Linear canonical transformed (LCT) function (§C) |
\(h\) | Impulse response function |
\(\tilde h \) | Impulse response function with reduced coordinate; Point spread function (§13.2.1) |
\(\tilde h_d\) | Defocused impulse response function for Gaussian pupil (§13.2.2) |
\(h_{dr}\) | Defocused impulse response function for rectangular pupil (§D) |
\(h_L\) | Time-lens impulse response function (§10.3, §13.2) |
\(\boldsymbol{\mathbf{H}}\) | Magnetic field (vector) (Table §3.1) |
\(H\) | (Shannon's) entropy (§5.2.1) |
\(H\) | Transfer function |
\(H_d\) | Amplitude transfer function (ATF) of generalized Gaussian pupil (§13) |
\(H_{dr}\) | Amplitude transfer function (ATF) of generalized rectangular pupil (§13) |
\(H_L\) | Time lens transfer function (§10.3) |
\({\cal H}\) | Hilbert transform (§6) |
\({\cal H}^{-1}\) | Inverse Hilbert transform (§6) |
\({\cal H}\) | Optical transfer function (§13) |
\({\cal H}_d\) | Defocused optical transfer function with Gaussian pupil (§13) |
\({\cal H}_{dr}\) | Defocused optical transfer function with rectangular pupil (§13) |
\(i\) | \(\sqrt{-1}\) |
\(I\) | Intensity |
\(I\) | Frequency interval (§15.10.1) |
\(I_{coh}\) | Coherent part of intensity (§8.2.1) |
\(I_{inc}\) | Incoherent part of intensity (§8.2.1) |
\(I_{max}\) | Maximum intensity (interference) |
\(I_{min}\) | Maximum intensity (interference) |
\(I_{tot}\) | Total intensity (§8.2.1) |
\(I_0\) | Object intensity (§4) |
\(I_1\) | Image intensity (§4) |
\(I_r\) | Intensity (radial) (Table §3.1) |
\(I_\theta\) | Intensity (azimuth) (Table §3.1) |
\(I_\phi\) | Intensity (elevation) (Table §3.1) |
\(J_n\) | Bessel function of the first kind of order \(n\) |
\(k\) | Wavenumber; Spatial frequency |
\(k_x\) | Horizontal component of spatial frequency (Table §1.2) |
\(k_y\) | Vertical component of spatial frequency (Table §1.2) |
\(\boldsymbol{\mathbf{k}}\) | Wavenumber vector |
\(k_c\) | Wavenumber at carrier frequency |
\(k_i\) | Imaginary-part of wavenumber function (absorption) (§3.4.2) |
\(k_r\) | Real-part of wavenumber function (dispersion) (§3.4.2) |
\(K\) | Gain (§5.3.1) |
\(K\) | Stiffness (§11.6.1) |
\(K\) | Loop gain (§9.3) |
\(K_{BM}\) | Passive basilar membrane stiffness (§11.6.1) |
\(K_f\) | Filter DC gain (§9.3) |
\(K_m\) | Phase detector sensitivity (§9.3) |
\(K_v\) | Voltage controller oscillator gain (§9.3) |
\(l\) | Integer |
\({\mathscr L}(T) \) | Linear canonical transform (LCT) for kernel operator \(T\) (§C) |
\(m\) | Integer |
\(m\) | Message (baseband) function (§5.3.1) |
\(m\) | Modulation depth (audibility, contrast) |
\(m\) | Frequency slope (chirpiness) (§B.3) |
\(M\) | Magnification |
\(M'\) | Complex magnification (defocused system) (§12.2.2) |
\(M^*, M_f, M_{f'}, M_{f'}^*\) | Distorted magnification under binaural diplacusis (§17.3.3) |
\(m_0\) | Chirp slope of object (§12.4.1) |
\(M_0\) | Magnification \(-v/u\) |
\(m_1\) | Chirp slope of image (§12.4.1) |
\(m_r\) | Rectangular pulse chirp slope (§B.3) |
\(n\) | Index of refraction |
\(n\) | Noise time-signal (§5.3.1) |
\(n\) | Harmonic number |
\(n\) | Integer |
\(n_k\) | Neural group velocity dispersion coefficient (§11.7.3) |
\(N\) | Noise power (§5.2.1) |
\(N\) | Number of samples |
\(N\) | Schroeder phase number of harmonics (§12.4.1) |
\(N\) | Number of pulses in sequence (§E) |
\(NS\) | Nonstationarity index (§A.4) |
\(p\) | Pressure |
\(p\) | Probability (§5.2.1) |
\(P\) | Pressure (frequency domain) |
\(P\) | Pupil function |
\({\cal P}\) | Cauchy principal value (§6) |
\({\cal P}\) | Generalized pupil function (§13.2.2) |
\(P_e\) | Entrance pupil (§14.4.2) |
\(P_g\) | Gaussian pupil function (§13.2.2) |
\(P_r\) | Rectangular pupil function (§13.3.2, §D) |
\(q,q'\) | Linear canonical transform (LCT) variables (§C) |
\(Q\) | Q-factor of bandpass filter |
\(Q_{10}\) | Q-factor of bandpass filter at -10 dB points (§11.6.4) |
\(Q_{ERB}\) | Q-factor of bandpass filter at the ERB bandwidth (§11.6.4) |
\(r\) | Displacement |
\(r\) | Received signal time-signal (§5.3.1) |
\(r\) | Correlation coefficient (Pearson's r) |
\(\boldsymbol{\mathbf{r}}\) | Position vector |
\(r_c\) | Critical distance (§8.4.2) |
\(R\) | Fixed distance (§8.5) |
\(R\) | Synchronization strength/index (§85) |
\(R_{pp}\) | Autocorrelation function of \(p\) (§8.2.2) |
\(s\) | Time lens curvature |
\(s\) | Time signal |
\(s\) | Laplace-transform complex frequency (§9.4) |
\(s\) | Sampler delta function array (comb function) (§14) |
\(\hat{s}\) | Estimate of time signal (§3.3.3) |
\(s_{T,gg}\) | Curvature estimate of the gerbil and guinea pig time lens |
\(\boldsymbol{\mathbf{S}}\) | Poynting vector (Table §3.1) |
\(S, S_I\) | Intensity/power spectrum |
\(S\) | Signal power (§5.2.1) |
\(S\) | Power spectral density / Spectrum (§8) |
\(\mathit{S}\) | Surface area of room (§8.4.2) |
\(S\) | Imaginary part of Fresnel integral (§D) |
\(S_a\) | Amplitude spectrum (§13.3.3) |
\(s_h\) | Time-lens curvature in humans (§11.6.4) |
\(S_\omega\) | Acoustic point source strength (Table §3.1) |
\(t\) | Time |
\(t_0\) | Gaussian pulse width parameter of the object; Entrance pupil |
\(t_1\) | Gaussian pulse width parameter of the image; Exit pupil |
\(t'\) | Complex Gaussian pulse width parameter |
\(T\) | Period |
\(T\) | Integration time constant |
\(T\) | Complex tone standard (§15.11.1) |
\(T\) | Linear canonical transform (LCT) matrix operator (§C) |
\(\tilde T\) | Integration variable (§13.2.1) |
\(T_{60}\) | Reverberation time |
\(T_a\) | Aperture time |
\(T_c\) | Carrier period |
\(T_s\) | Sampling rate period |
\(v\) | Velocity (§3.3.3) |
\(v\) | Distance between lens and screen (§4) |
\(v\) | Neural group-delay dispersion |
\(V\) | Visibility (§7.2.1, §8) |
\(V\) | Volume (§8.4.2) |
\(V\) | Voltage (§11.6.1) |
\(v_g\) | Group velocity |
\(V_c\) | Output voltage from loop filter (§9.4) |
\(V_d\) | Output voltage from phase detector (§9.4) |
\(V_i\) | Input voltage to phase detector (§9.4) |
\(V_o\) | Output voltage from voltage controller oscillator (§9.4) |
\(v_p\) | Phase velocity |
\(v_{V-I}\) | Neural group-delay dispersion for the segment between wave I and wave V (§11.7.3) |
\(u\) | Acoustic velocity (Table §3.1) |
\(u\) | Distance between object and lens (§4) |
\(u\) | Auditory input (cochlear) group-delay dispersion |
\(\boldsymbol{\mathbf{u}}\) | Sound velocity (Table §3.1) |
\(u_e\) | External environment group-delay dispersion (§11) |
\(u_o\) | Outer-ear group-delay dispersion (§11) |
\(u_m\) | Middle-ear group-delay dispersion (§11) |
\(u_c\) | Cochlear group-delay dispersion (§11) |
\(w\) | Wave energy density (Table §3.1) |
\(W\) | Cross-spectral density (§8) |
\(W_d\) | Reciprocal defocus parameter \(=1/u + 1/v + 1/s\) (§13, §F) |
\(W_p\) | Single pulse duration (§E) |
\(x\) | x-axis coordinate |
\(x\) | In-phase modulation (§5.3.1) |
\(x\) | Real part of analytic signal; arbitrary time signal (§6) |
\(x\) | Defocus parameter \(=u+sv/(s+v)\) (§12.4.1, §17.3.1) |
\(X\) | Fourier transform of real part of analytic signal \(X\) (§6) |
\(x_0\) | Arbitrary spatial position (§3.2.2) |
\(y\) | y-axis coordinate |
\(y\) | Quadrature modulation (§5.3.1) |
\(x\) | Imaginary part of analytic signal (§6) |
\(z\) | Distance along the z-axis (the optical axis) |
\(z\) | Analytic signal (§6) |
\(X\) | Fourier transform of analytic signal \(Z\) (§6) |
\(Z_0\) | Characteristic impedance (Table §3.1) |
\(\alpha,\beta,\gamma\) | Direction cosines of wavenumber vector (§4.2.2) |
\(\alpha\) | Instantaneous phase of complex degree of coherence \(\gamma\) (§8) |
\(\alpha\) | Total absorption (\(=k_i\)) (§10, §B) |
\(\alpha\) | Gaussian shape factor (§12.5.3) |
\(\alpha'\) | Phase-velocity absorption (§B) |
\(\alpha”\) | Group-velocity absorption (§10, §B) |
\(\mathit{\alpha}\) | Absorption coefficient (§8.4.2) |
\(\beta\) | Total dispersion (\(=k_r\)) (§10, §B) |
\(\beta'\) | Phase-velocity absorption (§10, §B) |
\(\beta”\) | Group-velocity dispersion (§10, §11, §12, §B) |
\(\gamma\) | Frequency deviation (§6.5.3) |
\(\gamma\) | Mutual coherence function (§8) |
\(\gamma_{ii} \) | Self-coherence function of input signal (§9.5) |
\(\gamma_{oo} \) | Self-coherence function of output signal (§9.5) |
\(\gamma_{io} \) | Coherence function between input and output signals (§9.5) |
\(\Gamma\) | Complex degree of coherence (§8, §9.5) |
\(\delta\) | Dirac delta function |
\(\delta\) | Linear phase of coherence function (§8) |
\(\delta_{nm}\) | Kronecker delta |
\(\Delta f\) | Spectral bandwidth of narrowband signal |
\(\Delta f, \Delta f_{beat}\) | Frequency spacing between beating tones (§F) |
\(\Delta f, \Delta f_{oct}\) | Octave stretch in cents (§15.10.1, §F) |
\(\Delta f'\) | Iterated octave stretch in cents (§15.10.1) |
\(\Delta f_h\) | Bandwidth of the time-lens phase modulation in humans (§11.6.4) |
\(\Delta k\) | Wavenumber difference between beating components (§3.2.1) |
\(\Delta l\) | Coherence length (§8.2.4) |
\(\Delta n\) | Path change in index of refraction (§11.6.1) |
\(\Delta t\) | Deviation from complex tone standard (§15.11.1) |
\(\Delta t_{opt}\) | Optimal ratio between geometrical and dispersive blurs (Table §12.2, §13.2.2) |
\(\Delta \tau\) | Coherence time |
\(\Delta \omega\) | Frequency difference between beating components (§3.2.1) |
\(\Delta \omega\) | Bandwidth of narrowband signal |
\(\Delta \omega\) | Phase ramp (§6.3) |
\(\Delta \omega\) | Phase ramp (§6.3) |
\(\dot{\omega}\) | Frequency velocity (§6.3) |
\(\ddot{\omega}\) | Frequency acceleration (§6.3) |
\(\epsilon\) | Dielectric constant (permittivity) (Table §3.1) |
\(\epsilon_0\) | Dielectric constant in vacuum (permittivity) (Table §3.1) |
\(\zeta\) | z-axis coordinate in the traveling pulse coordinate system (§10,§11, §12.2) |
\(\zeta\) | Damping factor (Figure §9.3) |
\(\eta\) | Displacement function (§3.3.1) |
\(\eta\) | Mask coordinate (§4.2.2) |
\(\theta\) | Azimuth (Table §3.1) |
\(\theta\) | Angle from optical axis (§4) |
\(\theta_{min}\) | Angular resolution (§4.2.2) |
\(\kappa\) | Adiabatic compressibility (Table §3.1) |
\(\lambda\) | Wavelength |
\(\Lambda\) | Triangle function |
\(\lambda_n\) | Eigenvalue (§8.2.6) |
\(\mu\) | Magnetic permeability (Table §3.1) |
\(\mu\) | Spectral degree of coherence (§8) |
\(\mu_0\) | Magnetic permeability in vacuum (Table §3.1) |
\(\xi\) | Mask coordinate (§4.2.2) |
\(\rho\) | Fluid density (Table §3.1) |
\(\rho_{BM}\) | Basilar membrane density per unit length (§11.6.1) |
\(\sigma\) | Multiplicative factor (§12.4.2, §F) |
\(\tau\) | Time lag |
\(\tau\) | Time coordinate in the traveling pulse coordinate system, group delay |
\(\tilde\tau_0 \) | Reduced coordinate of the object time (§13.2.1) |
\(\tau_0\) | Initial time of pulse in the traveling pulse coordinate system |
\(\tau_1,\tau_2\) | Time constants (Figure §9.3) |
\(\tau_e\) | Effective duration (§8.3.2, §A) |
\(\tau_g\) | Group delay |
\(\tau_p\) | Phase delay |
\(\varphi\) | Phase function (time domain) |
\(\phi\) | Phase function (frequency domain) |
\(\phi\) | Elevation (Table §3.1) |
\(\phi_e\) | Phase error (§9.3) |
\(\phi_n\) | Schroeder phase for component \(n\) (§12.4.1) |
\(\phi_{\Delta f/2}\) | Time-lens phase at the cutoff frequencies of \(Q_{10}\) (§11.6.4) |
\(\psi\) | Field function (§3.2.1) |
\(\Psi\) | Eigenfunction (§3.3.1, §8.2.6) |
\(\omega\) | Angular frequency; Modulation frequency |
\(\bar{\omega}\) | First moment of frequency (§8) |
\(\Omega\) | Integration domain including radiating source and receivers (§8.2.6) |
\(\omega_c\) | Carrier angular frequency |
\(\omega_{coh}\) | Coherent amplitude transfer function cutoff frequency (Gaussian pupil) (§13) |
\(\omega_{coh,r}\) | Coherent amplitude transfer function cutoff frequency (rectangular pupil) (§13) |
\(\omega_H\) | Hold-in range (§9.3) |
\(\omega_{inc}\) | Incoherent modulation transfer function cutoff frequency (Gaussian pupil) (§13) |
\(\omega_L\) | Lock range (§9.3) |
\(\omega_m\) | Modulation angular frequency |
\(\omega_O\) | Pull-out range (§9.3) |
\(\omega_P\) | Pull-in range (§9.3) |